Spiropyrrolidine beta-secretase inhibitors for the treatment of alzheimer&#39;S disease

ABSTRACT

The present invention is directed to spiropyrrolidine compounds of formula (I) which are inhibitors of the beta-secretase enzyme and that are useful in the treatment of diseases in which the beta-secretase enzyme is involved, such as Alzheimer&#39;s disease. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the treatment of such diseases in which the beta-secretase enzyme is involved.

FIELD OF THE INVENTION

The invention is directed to spiropyrrolidine compounds which are useful as inhibitors of the beta secretase enzyme, and are useful in the treatment of diseases in which the beta secretase enzyme is involved, such as Alzheimer's Disease.

BACKGROUND OF THE INVENTION

Alzheimer's disease is characterized by the deposition of amyloid in the brain in the form of extra-cellular plaques and intra-cellular neurofibrillary tangles. The rate of amyloid accumulation is a function of the rates of formation, aggregation and egress from the brain. It is generally accepted that the main constituent of amyloid plaques is the 4 kD amyloid protein (βA4, also referred to as Aβ, β-protein and βAP) which is a proteolytic product of a precursor protein of much larger size. The amyloid precursor protein (APP or AβPP) has a receptor-like structure with a large ectodomain, a membrane spanning region and a short cytoplasmic tail. The Aβ domain encompasses parts of both extra-cellular and transmembrane domains of APP, thus its release implies the existence of two distinct proteolytic events to generate its NH₂- and COOH-termini. At least two secretory mechanisms exist which release APP from the membrane and generate soluble, COOH-truncated forms of APP (APP_(S)). Proteases that release APP and its fragments from the membrane are termed “secretases.” Most APP_(S) is released by a putative α-secretase which cleaves within the Aβ protein to release α-APP_(S) and precludes the release of intact Aβ. A minor portion of APP_(S) is released by a β-secretase (“β-secretase”), which cleaves near the NH₂-terminus of APP and produces COOH-terminal fragments (CTFs) which contain the whole Aβ domain.

Thus, the activity of β-secretase or β-site amyloid precursor protein-cleaving enzyme (“BACE”) leads to the cleavage of APP, production of Aβ, and accumulation of β-amyloid plaques in the brain, which is characteristic of Alzheimer's disease (see R. N. Rosenberg, Arch. Neurol., vol. 59, September 2002, pp. 1367-1368; H. Fukumoto et al, Arch. Neurol., vol. 59, September 2002, pp. 1381-1389; J. T. Huse et al, J. Biol. Chem., vol 277, No. 18, issue of May 3, 2002, pp. 16278-16284; K. C. Chen and W. J. Howe, Biochem. Biophys. Res. Comm, vol. 292, pp 702-708, 2002). Therefore, therapeutic agents that can inhibit β-secretase or BACE may be useful for the treatment of Alzheimer's disease.

The compounds of the present invention are useful for treating Alzheimer's disease by inhibiting the activity of β-secretase or BACE, thus preventing the formation of insoluble Aβ and arresting the production of Aβ.

SUMMARY OF THE INVENTION

The present invention is directed to spiropyrrolidine compounds of general formula (I)

and pharmaceutically acceptable salts thereof, which are useful as inhibitors of the β-secretase enzyme.

The invention is also directed to pharmaceutical compositions which include a therapeutically effective amount of a compound of formula (I), or pharmaceutically acceptable salts thereof, and a pharmaceutically acceptable carrier. The invention is also directed to methods of treating mammals for diseases in which the β-secretase enzyme is involved, such as Alzheimer's disease, and the use of the compounds and pharmaceutical compositions of the invention in the treatment of such diseases.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, the present invention is directed to spiropyrrolidine compounds represented by general formula (I)

and pharmaceutically acceptable salts thereof, wherein: V is selected from the group consisting of

(1) C, or

(2) N, and the dotted line leading to V represents an optional double bond, and is present

when V is C and is absent when V is N;

or V is selected from the group consisting of

(1) C, or

(2) N, and the real line and optional dotted line leading to V represent a single bond or an optional double bond, and represent a single bond when V is N;

Q is selected from the group consisting of

(1) ═CR¹⁰—,

(2) ═N—,

(3) —(N→O)—,

(4) —O—, or

(5) ═S—;

Y is selected from the group consisting of

(1) ═CR¹⁰—,

(2) —CR¹⁰═,

(3) ═CR¹⁰—CR¹¹═,

(4) ═CR¹⁰—N═, or

(5) ═N—CR¹⁰═;

Z is selected from the group consisting of

(1) ═CR¹⁰—,

(2) —N—,

(3) —O—, or

(4) ═S—;

provided that Q, Y and Z together with V and the neighboring C atom form a fused aromatic 5- or 6-membered ring;

X¹-X² is selected from the group consisting of

(1) —CR¹⁰R¹¹—CR¹²CR¹³,

(2) —CR¹⁰R¹¹—O—,

(3) —O—CR¹⁰R¹¹—,

(4) —CR¹⁰R¹¹—NR¹²—,

(5) —NR¹²—CR¹⁰R¹¹—,

(6) —CR¹⁰R¹¹—S(═O)mR¹²—,

(7) —S(═O)mR¹²—, CR¹⁰R¹¹—,

(8) —CR¹⁰R¹¹—CR¹²CR¹³—O—,

(9) —CR¹⁰R¹¹—CR¹²CR¹³—,

(10) —CR¹⁰R¹¹—O—CR¹²CR¹³,

(11) —CR¹⁰R¹¹—CR¹²CR¹³NR¹⁴—, or

(12) —O—CR¹⁰R¹¹—CR¹²CR¹³—, or

(13) —S(═O)pR¹²—CR¹⁰R¹¹—;

R¹ is selected from the group consisting of

-   -   (1) hydrogen     -   (2) C₁₋₆alkyl,     -   (3) C₂₋₆alkenyl,     -   (4) —C₃₋₉ cycloalkyl,     -   (5) —C₆₋₁₀aryl,     -   (6) heteroaryl group having from 5 to 12 ring atoms, wherein at         least one ring atom is a heteroatom selected from the group         consisting of nitrogen, sulfur or oxygen,     -   (7) a heterocyclic group having 4 to 8 ring atoms, wherein at         least one ring atom is a heteroatom selected from the group         consisting of nitrogen, sulfur or oxygen,     -   wherein said alkyl, alkenyl, aryl, cycloalkyl, heterocyclic or         heteroaryl R¹ moiety is optionally substituted with one or more         -   (a) halo,         -   (b) —OH,         -   (c) —CN,         -   (d) —C₁₋₆ alkyl,         -   (e) —C₃₋₈ cycloalkyl,         -   (f) —O—C₁₋₆ alkyl,         -   (g) —O—CH₂—C₆₋₁₀aryl,         -   (h) —C₆₋₁₀aryl,         -   (i) heteroaryl group having from 5 to 12 ring atoms, wherein             at least one ring atom is a heteroatom selected from the             group consisting of nitrogen, sulfur or oxygen,         -   (j) oxo,         -   (k) a heterocyclic group having 4 to 8 ring atoms, wherein             at least one ring atom is a heteroatom selected from the             group consisting of nitrogen, sulfur or oxygen,         -   (l) —O—CH₂—C₃₋₈ cycloalkyl,         -   (m) —C(═O)—C₁₋₆ alkyl, or         -   (n) —NR^(5A)R^(5B),             R² and R³ are independently selected from the group             consisting of:     -   (1) hydrogen,     -   (2) OH,     -   (3) —C₁₋₆ alkyl,     -   (4) —CN,     -   (5) —C₆₋₁₀ aryl, or     -   (6) heteroaryl group having from 5 to 12 ring atoms, wherein at         least one ring atom is a heteroatom selected from the group         consisting of nitrogen, sulfur or oxygen,     -   wherein said alkyl, aryl or heteroaryl R² or R³ moiety is         optionally substituted with one or more         -   (a) halo,         -   (b) —C₁₋₆ alkyl, wherein said alkyl is optionally             substituted with one or more halogen, and         -   (c) —O—C₁₋₆ alkyl,             or R² and R³ are linked together to form cyclic group of             4-10 ring carbon atoms, wherein one or two of the ring             carbon atoms is replaced by an oxygen, nitrogen or sulfur;             R^(5A) and R^(5B) are independently selected from the group             consisting of     -   (1) hydrogen,     -   (2) —C₁₋₆ alkyl,     -   (3) —C(═O)—(O)_(m)—C₁₋₆ alkyl,     -   (4) —C(═O)—(O)_(m)—C₆₋₁₀ aryl,     -   (5) —SO₂—C₃₋₈ cycloalkyl,     -   (6) —SO₂—C₁₋₆ alkyl,     -   (4) —C(═O)—NR^(6A)R^(6B), wherein R^(6A) and R^(6B) are selected         from the group consisting of wherein the alkyl, cycloalkyl or         aryl moiety is optionally substituted with one or more         -   (a) halogen,         -   (b) hydroxyl,         -   (c) —O—C₁₋₆ alkyl, or         -   (d) —C(═O)—(O)_(m)—C₁₋₆ alkyl,     -   or R^(6A) and R^(6B) are linked together with the nitrogen to         which they are attached to form a 4-6 membered carbocyclic ring,         wherein one or two of the ring carbon atoms is optionally         replaced by a nitrogen, oxygen or sulfur, and the ring is         optionally substituted with one or more         -   (a) halogen,         -   (b) hydroxyl,         -   (c) C₁₋₆ alkyl,         -   (d) —O—C₁₋₆ alkyl,         -   (e) —C(═O)—(O)_(m)—C₁₋₆ alkyl, or         -   (f) —SO₂—C₁₋₆ alkyl;             R¹⁰, R¹¹, R¹², R¹³ and R¹⁴ are independently selected from             the group consisting of:     -   (1) hydrogen,     -   (2) —C₁₋₆ alkyl,     -   (3) hydroxyl,     -   (4) —(CH₂)_(m) C₆₋₁₀aryl     -   (5) —C₂₋₆alkenyl,     -   (6) —O—C₁₋₆alkyl,     -   (7) halogen,     -   (8) —SO₂—C₁₋₆alkyl,     -   (9) —NR^(5A)R^(5B),     -   (10) —C₃₋₈ cycloalkyl,     -   (11) —C(═O)—(O)_(m)—C₁₋₆ alkyl,     -   (12) —C(═O)—(O)_(m)—C₆₋₁₀ aryl,     -   (13) —C(═O)—NH—C₁₋₆ alkyl,     -   (14) —S(═O)₂—C₆₋₁₀ aryl,     -   wherein said alkyl, cycloalkyl, alkenyl or aryl moiety is         optionally substituted with one or more         -   (a) halo,         -   (b) hydroxyl,         -   (c) —C₁₋₆ alkyl,

(d) —NR^(5A)R^(5B),

-   -   (e) —O—C₁₋₆ alkyl, and     -   (f) —C₆₋₁₀aryl,     -   wherein said wherein said alky or aryl is optionally substituted         with one or more halo,     -   or any R¹⁰ and R¹¹, or any R¹² and R¹³, on identical carbon ring         atoms, are linked together to form an oxo group,     -   or any R¹⁰ and R¹¹, or any R¹² and R¹³, on identical carbon ring         atoms, are linked together to form an aromatic or non-aromatic         spirocyclic group of 5-10 ring carbon atoms, wherein one or two         of the ring carbon atoms is replaced by an oxygen, nitrogen or         sulfur,     -   or any R¹⁰ and R¹¹, or any R¹² and R¹³, on adjacent carbon ring         atoms, are linked together to form to form a fused aromatic or         non-aromatic cyclic group of 5-10 ring carbon atoms, wherein one         or two of the ring carbon atoms is replaced by an oxygen,         nitrogen or sulfur,         m is 0 or 1;         n is 0 or 1;         p is 0, 1 or 2;         and pharmaceutically acceptable salts thereof.

In particular embodiments of the compounds of formula (I), V is C and the dotted line leading to V represents a double bond. In other embodiments of the compounds of formula (I), V is n and the dotted line leading to V is absent.

In particular embodiments of the compounds of formula (I), -Q-Y—Z— together form the group —CR¹⁰═CR¹⁰—CR¹¹═CR¹⁰—, thereby forming a fused phenyl ring.

In other embodiments of the compounds of formula (I), -Q-Y—Z— together forms the groups —N═CR¹⁰—CR¹¹═CR¹⁰— or —CR¹⁰═CR¹⁰—CR¹¹═N—, thereby forming a fused pyridyl ring.

In other embodiments of the compounds of formula (I), -Q-Y—Z— together forms the group —N═CR¹⁰—CR¹¹═N— or —N═CR¹⁰—N═CR¹¹—, thereby forming a fused pyrimidinyl ring.

In other embodiments of the compounds of formula (I), -Q-Y—Z— together forms the group —NH—CR¹⁰═CR¹⁰—, —S—CR¹⁰═CR¹⁰—, —O—CR¹⁰═CR¹⁰—, —N═CR¹⁰—S—, —CR¹⁰═CR¹⁰═S— or —CR¹⁰═CR¹⁰—O—, thereby forming a five-membered heteroaryl ring.

In particular embodiments of the compounds of formula (I), X¹-X² is —CR¹⁰R¹¹—CR¹²CR¹³— and n is 0 or 1.

In other embodiments X¹-X² is —NR¹²—CR¹⁰R¹¹— or CR¹⁰R¹¹—NR¹²— and n is 1.

In other embodiments, X¹-X² is —S(═O)pR¹²—CR¹⁰R¹¹— and n is 1.

In other embodiments, X¹-X² is —CR¹⁰R¹¹—O— or —O—CR¹⁰R¹¹—, and n is 1.

In other embodiments, X¹-X² is one of —CR¹⁰R¹¹—NR¹⁴CR¹²R¹³—, —CR¹⁰R¹¹—O—CR¹²CR¹³—, —CR¹⁰R¹¹—CR¹⁴CR¹²NR¹³—, or —O—CR¹⁰R¹¹—CR¹²CR¹³—.

In particular embodiments of the compounds of formula (I), R¹ is selected from the group consisting of

-   -   (1) hydrogen     -   (2) C₁₋₆alkyl,     -   (3) C₃₋₉ cycloalkyl, or     -   (4) phenyl,     -   wherein said alkyl, cycloalkyl or phenyl R¹ moiety is optionally         substituted with one or more         -   (a) halo,         -   (b) —OH,         -   (c) —CN,         -   (d) —C₁₋₆ alkyl         -   (e) —C₃₋₆ cycloalkyl, or         -   (f) —O—C₁₋₆ alkyl.

In particular embodiments, R¹ is hydrogen, phenyl (optionally substituted with halogen), or cyclohexyl.

In particular embodiments of the compounds of formula (I), R² is hydrogen and R³ is selected from the group consisting of:

-   -   (1) hydrogen,     -   (2) C₆₋₁₀aryl (for example, phenyl), or     -   (3) heteroaryl,     -   wherein said aryl or heteroaryl R³ moiety is optionally         substituted with one or more         -   (a) halo,         -   (b) —C₁₋₆ alkyl, wherein said alkyl is optionally             substituted with one or more halogen, and         -   (c) —O—C₁₋₆ alkyl.

In particular embodiments, R² is hydrogen and R³ is hydrogen or unsubstituted phenyl.

In other embodiments, R² and R³ are linked together to form cyclic group of 4-10 ring carbon atoms, wherein one or two of the ring carbon atoms is replaced by an oxygen, nitrogen or sulfur.

The invention is also directed to methods of treating mammals for diseases in which the β-secretase enzyme is involved, such as Alzheimer's disease, by administering a therapeutically effective amount of a compound of any of the embodiments of formula (I).

The invention is also directed to pharmaceutical compositions which include an effective amount of a compound of any of the embodiments of formula (I) or pharmaceutically acceptable salts thereof, and a pharmaceutically acceptable carrier.

The invention is further directed to a method for the manufacture of a medicament or a composition for inhibiting β-secretase enzyme activity in humans and animals comprising combining a compound of any of the embodiments of formula (I) or a pharmaceutically acceptable salt thereof, with a pharmaceutical carrier or diluent.

In one embodiment, the invention is directed to methods of inhibiting BACE1 enzyme activity, by administering a therapeutically effective amount of a compound of any of the embodiments of formula (I).

In another embodiment, the invention is directed to methods of inhibiting BACE2 enzyme activity, by administering a therapeutically effective amount of a compound of any of the embodiments of formula (I).

The invention is also directed to a method for the manufacture of a medicament or a composition for treating Alzheimer's Disease in humans, comprising combining a compound of any of the embodiments of formula (I) or a pharmaceutically acceptable salt thereof, with a pharmaceutical carrier or diluent.

In some embodiments, the compound of formula (I) is a compound of formula (II)

and pharmaceutically acceptable salts thereof, wherein R², R⁵, X¹, X², Q, Y and Z are as defined above.

In particular embodiments of the compounds of formula (II), -Q-Y—Z— together form the group —CR¹⁰═CR¹⁰—CR¹¹═CR¹⁰—, thereby forming a fused phenyl ring.

In other embodiments of the compounds of formula (II), -Q-Y—Z— together forms the groups —N═CR¹⁰—CR¹¹═CR¹⁰— or —CR¹⁰═CR¹⁰—CR¹¹═N—, thereby forming a fused pyridyl ring.

In other embodiments of the compounds of formula (II), -Q-Y—Z— together forms a the group —N═CR¹⁰—CR¹¹═N— or —N═CR¹⁰—N═CR¹¹, thereby forming a fused pyrimidinyl ring.

In other embodiments of the compounds of formula (II), -Q-Y—Z— together forms the group —NH—CR¹⁰═CR¹⁰—, —S—CR¹⁰═CR¹⁰—, —O—CR¹⁰═CR¹⁰—, —N═CR¹⁰—S—, —CR¹⁰═CR¹⁰═S— or —CR¹⁰═CR¹⁰—O—, thereby forming a five-membered heteroaryl ring.

In particular embodiments of the compounds of formula (II), X¹-X² is —CR¹⁰R¹¹—CR¹²CR¹³— and n is 0 or 1.

In other embodiments of the compounds of formula (II), X¹-X² is —NR¹²—CR¹⁰R¹¹— or CR¹⁰R¹¹— and n is 1.

In other embodiments of the compounds of formula (II), X¹-X² is —S(═O)pR¹²—CR¹⁰R¹¹— and n is 1.

In other embodiments of the compounds of formula (II), X¹-X² is —CR¹⁰R¹¹—O— or —O—CR¹⁰R¹¹—, and n is 0 or 1.

In other embodiments of the compounds of formula (II), X¹-X² is one of —CR¹⁰R¹¹—NR¹⁴CR¹²R¹³—, —CR¹⁰R¹¹—O—CR¹²CR¹³—, —CR¹⁰R¹¹—CR¹⁴CR¹²NR¹³—, or —O—CR¹⁰R¹¹—CR¹²CR¹³—.

In particular embodiments of the compounds of formula (II), R² is hydrogen and R³ is selected from the group consisting of:

-   -   (1) hydrogen,     -   (2) aryl (for example, phenyl), or     -   (3) heteroaryl,     -   wherein said aryl or heteroaryl R³ moiety is optionally         substituted with one or more         -   (a) halo,         -   (b) —C₁₋₆ alkyl, wherein said alkyl is optionally             substituted with one or more halogen, and         -   (c) —O—C₁₋₆ alkyl.

In particular embodiments of the compounds of formula (II), R² is hydrogen and R³ is hydrogen or unsubstituted phenyl.

In some embodiments, the compound of formula (I) is a compound of formula (III)

and pharmaceutically acceptable salts thereof, wherein R², R⁵, X¹, X², Q, Y and Z are as defined above.

In particular embodiments of the compounds of formula (III), -Q-Y—Z— together form the group —CR¹⁰═CR¹⁰—CR¹¹═CR¹⁰—, thereby forming a fused phenyl ring.

In other embodiments of the compounds of formula (III), -Q-Y—Z— together forms the groups —N═CR¹⁰—CR¹¹═CR¹⁰— or —CR¹⁰═CR¹¹═N—, thereby forming a fused pyridyl ring.

In other embodiments of the compounds of formula (III), -Q-Y—Z— together forms the group —N═CR¹⁰—CR¹¹═N— or —N═CR¹⁰—N═CR¹¹—, thereby forming a fused pyrimidinyl ring.

In other embodiments of the compounds of formula (III), -Q-Y—Z— together forms the group —NH—CR¹⁰═CR¹⁰—, —S—CR¹⁰═CR¹⁰—, —O—CR¹⁰═CR¹⁰—, —N═CR¹⁰—S—, —CR¹⁰═CR¹⁰═S— or —CR¹⁰═CR¹⁰—O—, thereby forming a five-membered heteroaryl ring.

In particular embodiments of the compounds of formula (III), X¹-X² is —CR¹⁰R¹¹—CR¹²CR¹³— and n is 0 or 1

In other embodiments of the compounds of formula (III), X¹-X² is NR¹²—CR¹⁰R¹¹— or —CR¹⁰R¹¹—NR¹²— and n is 1.

In other embodiments of the compounds of formula (III), X¹-X² is —S(═O)pR¹²—CR¹⁰R¹¹— and n is 1.

In other embodiments of the compounds of formula (III), X¹-X² is —CR¹⁰R¹¹—O— or —O—CR¹⁰R¹¹—, and n is 1.

In other embodiments of the compounds of formula (III), X¹-X² is one of —CR¹⁰R¹¹—NR¹⁴CR¹²R¹³—, —CR¹⁰R¹¹—O—CR¹²CR¹³—, —CR¹⁰R¹¹—CR¹⁴CR¹²NR¹³—, or —O—CR¹⁰R¹¹—CR¹²CR¹³—.

In some embodiments, the compound of formula (I) is a compound of formula (IV)

and pharmaceutically acceptable salts thereof, wherein R², R³, R⁴, R⁵, X¹ and X² are as defined above.

In particular embodiments of the compounds of formula (IV), X¹-X² is —CR¹⁰R¹¹—CR¹²CR¹³— and n is 0 or 1.

In other embodiments of the compounds of formula (IV), X¹-X² is NR¹²—CR¹⁰R¹¹— or —CR¹⁰R¹¹—NR¹²— and n is 1.

In other embodiments of the compounds of formula (IV), X¹-X² is —S(═O)pR¹²—CR¹⁰R¹¹— and n is 1.

In other embodiments of the compounds of formula (IV), X¹-X² is cR¹⁰R¹¹—O— or —O—CR¹⁰R¹¹— and n is 1 or 2.

In other embodiments of the compounds of formula (IV), X¹-X² is one of —CR¹⁰R¹¹—NR¹⁴CR¹²R¹³—, —CR¹⁰R¹¹—O—CR¹²CR¹³—, —CR¹⁰R¹¹—CR¹⁴CR¹²NR¹³—, or —O—CR¹⁰R¹¹—CR¹²CR¹³—.

In particular embodiments of the compounds of formula (IV), R¹ is selected from the group consisting of

-   -   (1) hydrogen     -   (2) C₁₋₆alkyl,     -   (3) C₃₋₆ cycloalkyl, or     -   (4) phenyl,         -   wherein said alkyl, cycloalkyl or phenyl R¹ moiety is             optionally substituted with one or more         -   (a) halo,         -   (b) —OH,         -   (c) —CN,         -   (d) —C₁₋₆ alkyl         -   (e) —C₃₋₆ cycloalkyl, or         -   (f) —O—C₁₋₆ alkyl.

In particular embodiments of the compounds of formula (IV), R¹ is hydrogen, phenyl (optionally substituted with halogen), or cyclohexyl.

In particular embodiments of the compounds of formula (IV), R² is hydrogen and R³ is selected from the group consisting of:

-   -   (1) hydrogen,     -   (2) aryl (for example, phenyl), or     -   (3) heteroaryl,     -   wherein said aryl or heteroaryl R³ moiety is optionally         substituted with one or more         -   (a) halo,         -   (b) —C₁₋₆ alkyl, wherein said alkyl is optionally             substituted with one or more halogen, and         -   (c) —O—C₁₋₆ alkyl.

In particular embodiments of the compounds of formula (IV), R² is hydrogen and R³ is hydrogen or unsubstituted phenyl.

In other embodiments of the compounds of formula (IV), R² and R³ are linked together to form cyclic group of 4-10 ring carbon atoms, wherein one or two of the ring carbon atoms is replaced by an oxygen, nitrogen or sulfur.

In some embodiments, the compound of formula (I) is a compound of formula (V)

and pharmaceutically acceptable salts thereof, wherein R², R³, R⁴, R⁵, X¹ and X² are as defined above.

In particular embodiments of the compounds of formula (V), X¹-X² is —CR¹⁰R¹¹—CR¹²CR¹³— and n is 0 or 1

In other embodiments of the compounds of formula (V), X¹-X² is NR¹²—CR¹⁰R¹¹— or —CR¹⁰R¹¹—NR¹²— and n is 1.

In other embodiments of the compounds of formula (V), X¹-X² is —S(═O)pR¹²—CR¹⁰R¹¹— and n is 1.

In other embodiments of the compounds of formula (V), X¹-X² is —CR¹⁰R¹¹—O— or —O—CR¹⁰R¹¹—, and n is 1.

In other embodiments of the compounds of formula (V), X¹-X² is one of —CR¹⁰R¹¹—NR¹⁴CR¹²R¹³—, —CR¹⁰R¹¹—O—CR¹⁴CR¹²NR¹³—, or —O—CR¹⁰R¹¹—CR¹²CR¹³—.

In particular embodiments of the compounds of formula (V), R¹ is selected from the group consisting of

-   -   (1) hydrogen     -   (2) C₁₋₆alkyl,     -   (3) C₃₋₆ cycloalkyl, or     -   (4) phenyl,         wherein said alkyl, cycloalkyl or phenyl R¹ moiety is optionally         substituted with one or more         -   (a) halo,         -   (b) —OH,         -   (c) —CN,         -   (d) —C₁₋₆ alkyl         -   (e) —C₃₋₆ cycloalkyl, or         -   (f) —O—C₁₋₆ alkyl.

In particular embodiments of the compounds of formula (V), R¹ is hydrogen, phenyl (optionally substituted with halogen), or cyclohexyl.

In particular embodiments of the compounds of formula (V), R² is hydrogen and R³ is selected from the group consisting of:

-   -   (1) hydrogen,     -   (2) aryl (for example, phenyl), or     -   (3) heteroaryl,     -   wherein said aryl or heteroaryl R³ moiety is optionally         substituted with one or more         -   (a) halo,         -   (b) —C₁₋₆ alkyl, wherein said alkyl is optionally             substituted with one or more halogen, and         -   (c) —O—C₁₋₆ alkyl.

In particular embodiments of the compounds of formula (V), R² is hydrogen and R³ is hydrogen or unsubstituted phenyl.

In other embodiments of the compounds of formula (V), R² and R³ are linked together to form cyclic group of 4-10 ring carbon atoms, wherein one or two of the ring carbon atoms is replaced by an oxygen, nitrogen or sulfur.

The invention is also directed to methods of treating mammals for diseases in which the β-secretase enzyme is involved, such as Alzheimer's disease, by administering a therapeutically effective amount of a compound of any of the embodiments of formulas (II) to (V).

The invention is also directed to pharmaceutical compositions which include an effective amount of a compound of any of the embodiments of formulas (II) to (V) or pharmaceutically acceptable salts thereof, and a pharmaceutically acceptable carrier.

The invention is further directed to a method for the manufacture of a medicament or a composition for inhibiting β-secretase enzyme activity in humans and animals comprising combining a compound of any of the embodiments of formulas (II) to (V) or a pharmaceutically acceptable salt thereof, with a pharmaceutical carrier or diluent.

In one embodiment, the invention is directed to methods of inhibiting BACE1 enzyme activity, by administering a therapeutically effective amount of a compound of any of the embodiments of formulas (II) to (V).

In another embodiment, the invention is directed to methods of inhibiting BACE2 enzyme activity, by administering a therapeutically effective amount of a compound of any of the embodiments of formulas (II) to (V).

The invention is also directed to a method for the manufacture of a medicament or a composition for treating Alzheimer's Disease in humans, comprising combining a compound of any of the embodiments of formulas (II) to (V) or a pharmaceutically acceptable salt thereof, with a pharmaceutical carrier or diluent.

In another embodiment, the invention is directed to compounds of Examples 1—as described herein, or pharmaceutically acceptable salts thereof.

As used herein, the definitions of each of Q-Y—Z should read from left to right, so that when Q is ═CR¹⁰—, Y is ═CR¹⁰—CR¹¹═ and Z is ═CR¹⁰—, the formula (I) ring structure should appear as follows:

As used herein, the definitions of X¹-X² are read from left to right, so that when X¹-X² is —CR¹⁰R¹¹═CR¹²CR¹³—, the formula (I) ring structure should appear as follows:

As used herein, the term “alkyl,” by itself or as part of another substituent, means a saturated straight or branched chain hydrocarbon radical having the number of carbon atoms designated (e.g., C₁₋₁₀ alkyl means an alkyl group having from one to ten carbon atoms). Suitable alkyl groups for use in the invention are C₁₋₆ alkyl groups, having from one to six carbon atoms. Exemplary alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, and the like.

The term “C₀ alkyl,” for example in the term “—C₀alkyl-C₆₋₁₂ aryl”, refers to a bond.

As used herein, the term “alkenyl,” by itself or as part of another substituent, means a straight or branched chain hydrocarbon radical having a single carbon-carbon double bond and the number of carbon atoms designated (e.g., C₂₋₁₀ alkenyl means an alkenyl group having from two to ten carbon atoms). Suitable alkenyl groups for use in the invention are C₂₋₆ alkenyl groups, having from two to six carbon atoms. Exemplary alkenyl groups include ethenyl and propenyl.

Suitable cycloalkyl groups for use in the invention are monocyclic C₃₋₈ cycloalkyl groups, having from three to eight carbon atoms. Exemplary monocyclic cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. Exemplary bridged cycloalkyl groups include adamantly and norbornyl. Exemplary fused cycloalkyl groups include decahydronaphthalene.

As used herein, the term “heterocyclic,” by itself or as part of another substituent, means a cycloalkyl group as defined above, in which one or more of the ring carbon atoms is replaced with a heteroatom (such as N, S or O). Suitable non-aromatic heterocyclic groups for use in the invention include piperidinyl, piperazinyl, morpholinyl, tetrahydropyranyl, tetrahydrofuranyl, pyrrolidinyl, pyrazolidinyl and imidazolildinyl. In certain embodiments, heterocyclic groups for use in the invention have four to eight ring atoms and a single nitrogen or oxygen heteroatom.

When a heterocyclic group as defined herein is substituted, the substituent may be bonded to a ring carbon atom of the heterocyclic group, or to a ring heteroatom (i.e., a nitrogen, oxygen or sulfur), which has a valence which permits substitution. Similarly, when a heterocyclic group is defined as a substituent herein, the point of attachment may be at a ring carbon atom of the heterocyclic group, or on a ring heteroatom (i.e., a nitrogen, oxygen or sulfur), which has a valence which permits attachment.

As used herein, the term “aryl,” by itself or as part of another substituent, means an aromatic or cyclic radical having the number of carbon atoms designated (e.g., C₆₋₁₀ aryl means an aryl group having from six to ten carbons atoms). The term “aryl” includes multiple ring systems (such as fused ring systems) as well as single ring systems, and includes multiple ring systems wherein part of the molecule is aromatic and part is non-aromatic. A suitable single ring aryl group for use in the invention is phenyl. Suitable fused ring aryl groups include naphthyl, tetrahydronaphthyl and indanyl.

The term “halo” or “halogen” includes fluoro, chloro, bromo and iodo.

As used herein, the term “heteroaryl,” by itself or as part of another substituent, means an aromatic cyclic group having at least one ring heteroatom (O, N or S). The term “heteroaryl” includes multiple ring systems as well as single ring systems. Exemplary heteroaryl groups have from 5 to 12 ring atoms. Exemplary heteroaryl groups include pyrazinyl, pyrazolyl, pyridazinyl, pyridyl, pyrimidinyl, pyrrolyl, tetrazolyl, furanyl, imidazolyl, indazolyl, triazinyl, pyranyl, thiazolyl, thienyl, triazolyl, oxazolyl, isoxazolyl, thiazolyl, oxadiazolyl, indolyl, quinolinyl, isoquinolinyl, benzimidazolyl, benzofuranyl, indynyl and benzoxazolyl.

When a heteroaryl group as defined herein is substituted, the substituent may be bonded to a ring carbon atom of the heteroaryl group, or on a ring heteroatom (i.e., a nitrogen, oxygen or sulfur), which has a valence which permits substitution. Similarly, when a heteroaryl group is defined as a substituent herein, the point of attachment may be at a ring carbon atom of the heteroaryl group, or on a ring heteroatom (i.e., a nitrogen, oxygen or sulfur), which has a valence which permits attachment.

As used herein, the term “beta-secretase” or “β-secretase” refers to an enzyme that is sometimes known in the literature as “BACE”, “BACE1” (see, e.g., Vassar et al., 1999, Science 286:735-741), or “BACE2” (see, e.g., Farzan et al., 2000, PNAS 97:9712-9717). BACE1 is a 501 amino acid membrane-bound aspartic protease. BACE1 has all the known functional properties and characteristics of β-secretase. BACE2, also called Asp-1 or memapsin-1, is a second member of the BACE family of membrane-bound aspartic proteases. See Roggo, Current Topics in Medicinal Chemistry, 2002, 2:359-370, for a further discussion of the differences between BACE1 and BACE2.

The compounds of the invention are inhibitors of both the BACE1 and BACE2 enzyme.

The compounds of formula (I) have at least one asymmetric center. Additional asymmetric centers may be present depending upon the nature of the various substituents on the molecule.

Compounds with asymmetric centers give rise to enantiomers (optical isomers), diastereomers (configurational isomers) or both. All of the possible enantiomers and diastereomers in mixtures (as pure or partially purified compounds) are included within the scope of formula (I)

Compounds described herein may contain one or more double bonds, and may thus give rise to cis/trans isomers as well as other configurational isomers. The compounds of formula (I) include all such possible isomers as well as mixtures of such isomers.

Formula (I) is shown above without a definite stereochemistry at certain positions. Figure (I) as depicted includes all stereoisomers of formula (I) and pharmaceutically acceptable salts thereof.

The independent syntheses of the enantiomerically or diastereomerically enriched compounds, or their chromatographic separations, may be achieved as known in the art by appropriate modification of the methodology disclosed herein. Their absolute stereochemistry may be determined by the x-ray crystallography of crystalline products or crystalline intermediates that are derivatized, if necessary, with a reagent containing an asymmetric center of known absolute configuration.

If desired, racemic mixtures of the compounds may be separated so that the individual enantiomers or diastereomers are isolated. The separation can be carried out by methods well known in the art, such as the coupling of a racemic mixture of compounds to an enantiomerically pure compound to form a diastereomeric mixture, followed by separation of the individual diastereomers by standard methods, such as fractional crystallization or chromatography. The coupling reaction is often the formation of salts using an enantiomerically pure acid or base. The diastereomeric derivatives may then be converted to the pure enantiomers by cleavage of the added chiral residue. The racemic mixture of the compounds can also be separated directly by chromatographic methods using chiral stationary phases, which methods are well known in the art.

Alternatively, any enantiomer or diastereomer of a compound may be obtained by stereoselective synthesis using optically pure starting materials or reagents of known configuration by methods well known in the art.

The term “substantially pure” means that the isolated material is at least 90% pure, as assayed by analytical techniques known in the art. In one embodiment, the isolated material is at least 95% pure. In another embodiment, the isolated material is at least 99% pure.

The term “pharmaceutically acceptable salts” refers to salts prepared from pharmaceutically acceptable non-toxic bases or acids including inorganic or organic bases and inorganic or organic acids. The compounds of the invention may be mono, di or tris salts, depending on the number of acid functionalities present in the free base form of the compound. Free bases and salts derived from inorganic bases include aluminum, ammonium, calcium, copper, ferric, ferrous, lithium, magnesium, manganic salts, manganous, potassium, sodium, zinc, and the like. Particular salts are the ammonium, calcium, magnesium, potassium, and sodium salts. Salts in the solid form may exist in more than one crystal structure, and may also be in the form of hydrates. Salts derived from pharmaceutically acceptable organic non-toxic bases include salts of primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines, and basic ion exchange resins, such as arginine, betaine, caffeine, choline, N,N′-dibenzylethylene-diamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethyl-morpholine, N-ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperidine, polyamine resins, procaine, purines, theobromine, triethylamine, trimethylamine, tripropylamine, tromethamine, and the like. When the compound of the present invention is basic, salts may be prepared from pharmaceutically acceptable non-toxic acids, including inorganic and organic acids. Such acids include acetic, trifluoroacetic, benzenesulfonic, benzoic, camphorsulfonic, citric, ethanesulfonic, fumaric, gluconic, glutamic, hydrobromic, hydrochloric, isethionic, lactic, maleic, malic, mandelic, methanesulfonic, mucic, nitric, pamoic, pantothenic, phosphoric, succinic, sulfuric, tartaric, p-toluenesulfonic acid, and the like. Particular salts are the citric, hydrobromic, hydrochloric, trifluoroacetic, maleic, phosphoric, sulfuric, fumaric, and tartaric acids.

The present invention is directed to the use of the compounds of formulas (I) to (III) disclosed herein as inhibitors of β-secretase enzyme activity or β-site amyloid precursor protein-cleaving enzyme (“BACE”) activity, in a patient or subject such as a mammal in need of such inhibition, comprising the administration of an effective amount of the compound. The terms “-secretase enzyme,” “β-site amyloid precursor protein-cleaving enzyme,” and “BACE” are used interchangeably in this specification. In addition to humans, a variety of other mammals can be treated according to the method of the present invention.

The compounds of the present invention have utility in treating, ameliorating, controlling or reducing the risk of Alzheimer's disease. For example, the compounds may be useful for the prevention of dementia of the Alzheimer's type, as well as for the treatment of early stage, intermediate stage or late stage dementia of the Alzheimer's type. The compounds may also be useful in treating, ameliorating, controlling or reducing the risk of diseases mediated by abnormal cleavage of amyloid precursor protein (also referred to as APP), and other conditions that may be treated or prevented by inhibition of β-secretase. Such conditions include mild cognitive impairment, Trisomy 21 (Down Syndrome), cerebral amyloid angiopathy, degenerative dementia, Hereditary Cerebral Hemorrhage with Amyloidosis of the Dutch-Type (HCHWA-D), Creutzfeld-Jakob disease, prion disorders, amyotrophic lateral sclerosis, progressive supranuclear palsy, head trauma, stroke, pancreatitis, inclusion body myositis, other peripheral amyloidoses, diabetes and atherosclerosis.

The subject or patient to whom the compounds of the present invention is administered is generally a human being, male or female, in whom inhibition of β-secretase enzyme activity is desired, but may also encompass other mammals, such as dogs, cats, mice, rats, cattle, horses, sheep, rabbits, monkeys, chimpanzees or other apes or primates, for which inhibition of β-secretase enzyme activity or treatment of the above noted disorders is desired.

The compounds of the present invention may be used in combination with one or more other drugs in the treatment of diseases or conditions for which the compounds of the present invention have utility, where the combination of the drugs together are safer or more effective than either drug alone. Additionally, the compounds of the present invention may be used in combination with one or more other drugs that treat, prevent, control, ameliorate, or reduce the risk of side effects or toxicity of the compounds of the present invention. Such other drugs may be administered, by a route and in an amount commonly used therefor, contemporaneously or sequentially with the compounds of the present invention. Accordingly, the pharmaceutical compositions of the present invention include those that contain one or more other active ingredients, in addition to the compounds of the present invention. The combinations may be administered as part of a unit dosage form combination product, or as a kit or treatment protocol wherein one or more additional drugs are administered in separate dosage forms as part of a treatment regimen.

The term “composition” as used herein is intended to encompass a product comprising specified ingredients in predetermined amounts or proportions, as well as any product which results, directly or indirectly, from combination of the specified ingredients in the specified amounts. This term in relation to pharmaceutical compositions is intended to encompass a product comprising one or more active ingredients, and an optional carrier comprising inert ingredients, as well as any product which results, directly or indirectly, from combination, complexation or aggregation of any two or more of the ingredients, or from dissociation of one or more of the ingredients, or from other types of reactions or interactions of one or more of the ingredients.

Examples of combinations of the compounds of the present invention with other drugs in either unit dose or kit form include combinations with anti-Alzheimer's agents, for example other beta-secretase inhibitors or gamma-secretase inhibitors; glycine transport inhibitors, tau phosphorylation inhibitors; blockers of Aβ oligomer formation; p25/CDK5 inhibitors; HMG-CoA reductase inhibitors; PPAR gamma agonists, such as pioglitazone and rosiglitazone; NK1/NK3 receptor antagonists; NSAID's including ibuprofen; vitamin E; anti-amyloid antibodies, including anti-amyloid humanized monoclonal antibodies; COX-2 inhibitors; anti-inflammatory compounds, such as (R)-flurbiprofen; CB-1 receptor antagonists or CB-1 receptor inverse agonists; antibiotics such as doxycycline and rifampin; N-methyl-D-aspartate (NMDA) receptor antagonists, such as memantine and neramexane; NR2B antagonists; androgen receptor modulators; acetylcholinesterase inhibitors such as galantamine, rivastigmine, donepezil, and tacrine; mGluR5 modulators; growth hormone secretagogues such as ibutamoren, ibutamoren mesylate, and capromorelin; histamine H₃ antagonists; AMPA agonists; PDE IV inhibitors; GABA_(A) inverse agonists; GABA_(A) α 5 receptor ligands; GABA_(B) receptor ligands; potassium channel blockers; neuronal nicotinic agonists; P-450 inhibitors, such as ritonavir; or other drugs that affect receptors or enzymes that either increase the efficacy, safety, convenience, or reduce unwanted side effects or toxicity of the compounds of the present invention. The foregoing list of combinations is illustrative only and not intended to be limiting in any way.

In the pharmaceutical composition the active compound, which is a compound of the invention, is included in an amount sufficient to produce the desired effect upon the process or condition of diseases. Accordingly, the pharmaceutical compositions of the present invention encompass any composition made by admixing a compound of the invention and a pharmaceutically acceptable carrier.

The carrier may take a wide variety of forms depending on the form of preparation desired for administration, e.g., oral or parenteral (including intravenous). Thus, the pharmaceutical compositions of the invention can be presented as discrete units suitable for oral administration such as capsules, cachets or tablets each containing a predetermined amount of the active ingredient. Further, the compositions can be presented as a powder, as granules, as a solution, as a suspension in an aqueous liquid, as a non-aqueous liquid, as an oil-in-water emulsion or as a water-in-oil liquid emulsion. In addition to the common dosage forms set out above, the compounds of the invention, may also be administered by controlled release means and/or delivery devices.

Pharmaceutical compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets may contain a compound of the invention in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients may be, for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, corn starch, or alginic acid; binding agents, for example starch, gelatin or acacia, and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period.

A tablet containing a composition of this invention may be prepared by compression or molding, optionally with one or more accessory ingredients or adjuvants. Compressed tablets may be prepared by compressing, in a suitable machine, a compound of the invention in a free-flowing form such as powder or granules, optionally mixed with a binder, lubricant, inert diluent, surface active or dispersing agent. Molded tablets may be made by molding in a suitable machine, a mixture of the powdered compound moistened with an inert liquid diluent. In certain embodiments, each tablet contains from about 0.1 mg to about 500 mg of the active ingredient and each cachet or capsule contains from about 0.1 mg to about 500 mg of the compound of the invention.

Compositions for oral use may also be presented as hard gelatin capsules wherein the compound of the invention is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelatin capsules wherein the compound of the invention is mixed with water or an oil medium, for example peanut oil, liquid paraffin, or olive oil.

Other pharmaceutical compositions include aqueous suspensions, which contain the active materials in admixture with excipients suitable for the manufacture of aqueous suspensions. In addition, oily suspensions may be formulated by suspending the compound of the invention in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. Oily suspensions may also contain various excipients. The pharmaceutical compositions of the invention may also be in the form of oil-in-water emulsions, which may also contain excipients such as sweetening and flavoring agents.

The pharmaceutical compositions may be in the form of a sterile injectable aqueous or oleaginous suspension, or in the form of sterile powders for the extemporaneous preparation of such sterile injectable solutions or dispersions. In all cases, the final injectable form must be sterile and must be effectively fluid for easy syringability. The pharmaceutical compositions must be stable under the conditions of manufacture and storage, and should be preserved against the contaminating action of microorganisms such as bacteria and fungi.

Pharmaceutical compositions of the present invention can be in a form suitable for topical use such as, for example, an aerosol, cream, ointment, lotion, dusting powder, or the like. Further, the compositions can be in a form suitable for use in transdermal devices. These formulations may be prepared via conventional processing methods. As an example, a cream or ointment is prepared by mixing hydrophilic material and water, together with about 5 wt % to about 10 wt % of the compound of the invention, to produce a cream or ointment having a desired consistency.

Pharmaceutical compositions of this invention can also be in a form suitable for rectal administration wherein the carrier is a solid. Suitable carriers include cocoa butter and other materials commonly used in the art.

A “pharmaceutically acceptable excipient,” “pharmaceutically acceptable diluent,” “pharmaceutically acceptable carrier,” and “pharmaceutically acceptable adjuvant” means an excipient, diluent, carrier, and adjuvant that are useful in preparing a pharmaceutical composition that are generally safe, non-toxic and neither biologically nor otherwise-undesirable, and include an excipient, diluent, carrier, and adjuvant that are acceptable for veterinary use as well as human pharmaceutical use. “A pharmaceutically acceptable excipient, diluent, carrier and adjuvant” as used in the specification and claims includes both one and more than one such excipient, diluent, carrier, and adjuvant. By “pharmaceutically acceptable” it is meant the carrier, diluent or excipient must be compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.

Optional” or “optionally” means that the subsequently described event, circumstance, feature, or element may, but need not, occur, and that the description includes instances where the event or circumstance occurs and instances in which it does not. For example, “heterocyclo group optionally mono- or di-substituted with an alkyl group” means that the alkyl may, but need not, be present, and the description includes situations where the heterocyclo group is mono- or disubstituted with an alkyl group and situations where the heterocyclo group is not substituted with the alkyl group.

The terms “administration of” or “administering a” compound should be understood to mean providing a compound of the invention to the individual in need of treatment in a form that can be introduced into that individual's body in a therapeutically useful form and therapeutically useful amount, including, but not limited to: oral dosage forms, such as tablets, capsules, syrups, suspensions, and the like; injectable dosage forms, such as IV, IM, or IP, and the like; transdermal dosage forms, including creams, jellies, powders, or patches; buccal dosage forms; inhalation powders, sprays, suspensions, and the like; and rectal suppositories.

The terms “effective amount” or “therapeutically effective amount” means the amount of the subject compound that will elicit the biological or medical response of a tissue, system, animal or human that is being sought by the researcher, veterinarian, medical doctor or other clinician.

As used herein, the term “treatment” or “treating” means any administration of a compound of the invention to obtain a desired pharmacologic and/or physiologic effect. The effect may be prophylactic in terms of completely or partially preventing a disease or symptom thereof, and/or may be therapeutic in terms of a partial or complete cure for a disease and/or adverse affect attributable to the disease. Treatment includes (1) inhibiting the disease in an animal that is experiencing or displaying the pathology or symptomatology of the diseased (i.e., arresting further development of the pathology and/or symptomatology), or (2) ameliorating the disease in an animal that is experiencing or displaying the pathology or symptomatology of the diseased (i.e., reversing the pathology and/or symptomatology).

The terms “individual,” “subject,” and “patient,” used interchangeably herein, refer to a mammal, including, but not limited to, murines, simians, humans, mammalian farm animals, mammalian sport animals, and mammalian pets.

The compositions containing compounds of the invention may conveniently be presented in unit dosage form and may be prepared by any of the methods well known in the art of pharmacy.

The term “unit dosage form” is taken to mean a single dose wherein all active and inactive ingredients are combined in a suitable system, such that the patient or person administering the drug to the patient can open a single container or package with the entire dose contained therein, and does not have to mix any components together from two or more containers or packages. Typical examples of unit dosage forms are tablets or capsules for oral administration, single dose vials for injection, or suppositories for rectal administration. This list of unit dosage forms is not intended to be limiting in any way, but merely to represent typical examples of unit dosage forms.

Before the present invention is further described, it is to be understood that this invention is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.

It must be noted that as used herein and in the appended claims, the singular forms “a,” “and,” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation.

Publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.

The compositions containing compounds of the invention may conveniently be presented as a kit, whereby two or more components, which may be active or inactive ingredients, carriers, diluents, and the like, are provided with instructions for preparation of the actual dosage form by the patient or person administering the drug to the patient. Such kits may be provided with all necessary materials and ingredients contained therein, or they may contain instructions for using or making materials or components that must be obtained independently by the patient or person administering the drug to the patient.

When treating, ameliorating, controlling or reducing the risk of Alzheimer's disease or other diseases for which compounds of the invention are indicated, generally satisfactory results are obtained when the compounds of the invention are administered at a daily dosage of from about 0.1 mg to about 100 mg per kg of animal body weight. For example, the compounds may be given as a single daily dose or in divided doses two to six times a day, or in sustained release form. The total daily dosage is from about 1.0 mg to about 2000 mg (for example, from about 0.1 mg to about 20 mg per kg of body weight). In the case of a 70 kg adult human, the total daily dose will generally be from about 7 mg to about 1,400 mg. This dosage regimen may be adjusted to provide the optimal therapeutic response. The compounds may be administered on a regimen of 1 to 4 times per day, for example once or twice per day.

The amount of the compound of the invention that may be combined with the carrier materials to produce a single dosage form will vary depending upon the host treated and the particular mode of administration. For example, a formulation intended for the oral administration to humans may conveniently contain from about 0.005 mg to about 2.5 g of a compound of the invention, compounded with an appropriate and convenient amount of carrier material. Unit dosage forms will generally contain between from about 0.005 mg to about 1000 mg of the compound of the invention, typically 0.005 mg, 0.01 mg, 0.05 mg, 0.25 mg, 1 mg, 5 mg, 25 mg, 50 mg, 100 mg, 200 mg, 300 mg, 400 mg, 500 mg, 600 mg, 800 mg or 1000 mg, administered once, twice or three times a day.

It will be understood, however, that the specific dose level and frequency of dosage for any particular patient may be varied and will depend upon a variety of factors including the activity of the specific compound employed, the metabolic stability and length of action of that compound, the age, body weight, general health, sex, diet, mode and time of administration, rate of excretion, drug combination, the severity of the particular condition, and the host undergoing therapy.

The compounds of the invention may be prepared according to the following reaction Schemes, in which variables are as defined before or are derived, using readily available starting materials, from reagents and conventional synthetic procedures. It is also possible to use variants which are themselves known to those of ordinary skill in organic synthesis art, but are not mentioned in greater detail.

The present invention also provides a method for the synthesis of compounds useful as intermediates in the preparation of compounds of the invention.

Generic scheme I outlines a method for preparing compounds having different combination of 4-spiro fused aryl and amide substituents on the pyrrolidine ring. In this method, the appropriate cyclic ketone A is reacted with triethylphosphonoacetate to yield upon isolation the desired E-stereoisomer B which undergoes dipolar cycloaddition upon treatment with benzyl-N-(methoxymethyl)-trimethylsilylmethyl amine as an azomethine ylide precursor to provide the trans pyrrolidine C. The ester is hydrolyzed and coupled under standard conditions with a suitable amine E. Removal of the benzyl amine by either hydrogenation or other chemical methods such as a-chloroethyl chloroformate yields the target products F.

Generic Scheme II outlines a method for preparing 4-spirofused compounds that have a spiro ring substitution that is not compatible with hydrogenation conditions. In this method, the appropriate ketone is reacted with triethylphosphonoacetate to yield upon isolation the desired E-stereoisomer Bb which undergoes dipolar cycloaddition upon treatment with benzyl-N-(methoxymethyl)-trimethylsilylmethyl amine as an azomethine ylide precursor to provide the trans pyrrolidine Cc. The benzyl protecting group is then exchanged for a t-butoxycarbonyl by sequential treatment with 1-chloroethyl chloroformate, then methanol, and finally BOC anhydride to provide the BOC-protected pyrrolidine Dd. The ester is hydrolyzed and coupled under standard conditions with a suitable amine. TFA mediated deprotection of the t-butyl carbamate yields the desired product Ff.

Intermediate I: (2S,4R)-2-cyclohexyl-4-phenylpiperidine

Step 1: Benzyl 2-cyclohexyl-4-oxo-3,4-dihydropyridine-1(2H)-carboxylate

4-methoxypyridine (17.56 ml, 173 mmol) in THF (577 ml) at −30° C. was added benzyl chloroformate (24.70 ml, 173 mmol) dropwise. Stirred at −30° C. for 30 minutes and then added cyclohexylmagnesium chloride (200 ml, 260 mmol). Stirred for 30 minutes at −30° C. and quenched with 1N HCl. Extracted 3 times with diethyl ether. The combined organic fractions were combined, dried (Na_(z) SO₄), filtered and the solvent was evaporated under reduced pressure. Purified on silica gel 30% EtOAc/Hexanes affording 35.25 g.

¹H NMR (CDCl₃) δ 7.83 (br s, 1H), 7.42-7.36 (m, 5H), 5.34-5.24 (m, 3H), 4.38 (br s, 1H), 2.80-2.72 (m, 1H), 2.66-2.58 (m, 1H), 1.77-1.42 (m, 6H), 1.17-0.91 (m, 5H).

Step 2: Benzyl 2-cyclohexyl-4-oxopiperidine-1-carboxylate

Benzyl 2-cyclohexyl-4-oxo-3,4-dihydropyridine-1(2H)-carboxylate (35.25 g, 112 mmol) was dissolved in AcOH (450 ml) and added zinc dust (22.07 g, 337 mmol). The solution stirred at room temperature for 12 hours. The solution was filtered through celite and washed with EtOAc. The solvent was evaporated under reduced pressure and the product was purified by column chromatography on silica gel 30% EtOAc/Hexanes.

¹H NMR (CDCl₃) δ 7.40-7.31 (m, 5H), 5.22-5.14 (m, 2H), 4.54-4.21 (m, 2H), 3.19-3.08 (m, 1H), 2.62-2.43 (m, 3H), 2.35-2.27 (m, 1H), 1.82-1.53 (m, 6H), 1.42-0.80 (m, 5H).

Step 3: Benzyl 2-cyclohexyl-4-hydroxy-4-phenylpiperidine-1-carboxylate

Benzyl 2-cyclohexyl-4-oxopiperidine-1-carboxylate in THF (155 ml) was cooled to 0° C. and added phenylmagnesium bromide (22.08 ml, 61.8 mmol). The ice bath was removed and the solution stirred at room temperature for 14 hours. Quenched the reaction with 1N HCl and concentrated. Extracted three times with EtOAc and washed twice with water. The organics were dried, concentrated, and purified on silica gel 30% EtOAc.

¹H NMR (CDCl₃) δ 7.47-7.43 (m, 2H), 7.38-7.24 (m, 8H), 5.16 (s, 2H), 4.25-3.92 (m, 2H), 3.40-3.27 (m, 1H), 2.38-2.27 (m, 1H), 2.15-2.04 (m, 1H), 1.92-1.84 (m, 2H), 1.79-1.62 (m, 5H), 1.33-1.08 (m, 4H), 0.98-0.82 (m, 3H).

Step 4: Benzyl 2-cyclohexyl-4-phenyl-3,6-dihydropyridine-1(2H)-carboxylate

A solution of BF₃.OEt₂ (4.93 ml, 38.9 mmol) in CH₂Cl₂ (30 ml) was added to a stirred solution of benzyl 2-cyclohexyl-4-hydroxy-4-phenylpiperidine-1-carboxylate (5 g, 12.71 mmol) in CH₂Cl₂ (244 ml) at 0° C. The mixture was stirred at room temperature for 15 minutes. Saturated sodium bicarbonate (100 ml) was added after 15 minutes. Extracted twice with CH₂Cl₂ and the combined organics were dried and concentrated. The crude product was not purified.

¹H NMR (CDCl₃) δ 7.40-7.22 (m, 10H), 6.21-5.93 (m, 1H), 5.22-5.16 (m, 2H), 4.58-4.10 (m, 2H), 3.74-3.05 (m, 1H), 2.67-2.32 (m, 2H), 1.88-1.55 (m, 6H), 1.27-0.90 (m, 5H).

Step 5: 2-cyclohexyl-4-phenylpiperidine

Benzyl 2-cyclohexyl-4-phenyl-3,6-dihydropyridine-1(2H)-carboxylate (4.7 g, 12.52 mmol) in EtOH (25 ml) was added Pd/C (1.18 g, 0.554 mmol) and hydrogenated with a balloon for 10 hours. Filter through celite and concentrate. The crude piperidine was not purified. LRMS (M+H)=217.10

Step 6: Benzyl 2-cyclohexyl-4-phenylpiperidine-1-carboxylate

2-cyclohexyl-4-phenylpiperidine (2.85 g, 11.71 mmol) in CH₂Cl₂ (58.5 ml) was added benzyl chloroformate (2.507 ml, 17.56 mmol) and triethylamine (2.45 ml, 17.56 mmol). The reaction was stirred at room temperature for 2 hours. Added water and extracted 3 times with CH₂Cl₂. The combined organics were dried, concentrated, and purified on silica gel 20% EtOAc/Hexanes. Separated cis and trans on the AD column, 20% IPA/Hexanes w/DEA. Peak 1 corresponds to the cis racemic mixture with one trans diastereomer and peak2 is a single trans diastereomer. Obtained 2.5 g racemic cis/trans peak1. Resolved on the OJ column 20% EtOH/Hexanes w/DEA: Peak 1: 0.68 g pure cis undesired, peak 2 1.75 g cis/trans mixture.

¹H NMR (CDCl₃) δ 7.39-7.27 (m, 7H), 7.22-7.17 (m, 3H), 5.22-5.14 (m, 2H), 4.04-3.97 (m, 1H), 3.90-3.83 (m, 1H), 3.18-3.09 (m, 1H), 2.72-2.61 (m, 1H), 2.23-2.12 (m, 1H), 1.97-1.90 (m, 1H), 1.74-1.55 (m, 8H), 1.18-0.96 (m, 5H). LRMS (M+H)=378.99

Step 7: (2S,4R)-2-cyclohexyl-4-phenylpiperidine

Benzyl 2-cyclohexyl-4-phenylpiperidine-1-carboxylate (1.05 g, 2.78 mmol) in EtOH (50 ml) was added Pd/C (0.5 g, 0.235 mmol) and hydrogenated with a balloon overnight. Filtered through celite and concentrated. The trans isomer was removed on the chiral OD column 20% IPA/Hexanes w/DEA affording the single cis diastereomer.

¹H NMR (CDCl₃) δ 7.26-7.18 (m, 5H), 3.29-3.23 (m, 1H), 2.82-2.74 (m, 1H), 2.65-2.55 (m, 1H), 2.46-2.39 (m, 1H), 1.93-1.87 (m, 2H), 1.85-1.70 (m, 5H), 1.66-1.53 (m, 2H), 1.38-0.97 (m, 7H).

LRMS (M+H)=244.05

Intermediate II: (2S,4R)-2-(3,3-Difluorocyclohexyl)-4-phenylpiperidine

Step 1: 3-Oxocyclohex-1-en-1-yl trifluoromethanesulfonate

To a solution of 1 (50 g, 0.48 mmol) and 1,6-lutidine (103 g, 0.96 mmol) in 1 L of dry DCM was added Tf₂O (144 ml, 0.72 mmol) dropwise slowly at 0° C. The reaction mixture was stirred at 0° C. for 30 min, warmed to room temperature, stirred for 1 hour, and quenched with HCl (2.0 N). The mixture was partitioned between DCM and diluted aqueous HCl. The organic layer was washed with water and brine, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. Purification on silica gel afforded 2 as brown liquid (99 g, 85%).

Step 2: 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)cyclohex-2-en-1-one

To a solution of 2 (55 g, 0.227 mol) and bis-pinacolatodiboron (55.5 g, 0.250 mol) in 600 ml of dry dioxane was added K₂CO₃ (47 g, 0.341 mol), followed by Pd(PPh₃)Cl₂ (2.9 g, 6.8 mmol), PPh₃ (3.6 g, 13.6 mmol) under nitrogen. The mixture was refluxed for 4 hour, cooled to room temperature, and filtered. The filtrate was used in the next step directly.

Step 3: 3-(4-Phenylpyridin-2-yl)cyclohex-2-en-1-one

To a solution 3 (prepared above) in 800 ml of dioxane were added K₃PO₄ (118 g, 0.561 mol), 2-chloro-4-phenylpyridine (35.5 g, 0.187 mol), and Pd(dppf)Cl₂ (6 g, 5.6 mmol). The suspension was stirred at 80° C. overnight, filtered, and concentrated in vacuo. Purification on silica gel afforded 4 as a yellow solid (30 g, 64%).

Step 4: 3-(4-Phenylpyridin-2-yl)cyclohexanone

A suspension of 4 (30 g, 0.12 mol) and 2 g of Pd—C in 500 ml of ethyl acetate was hydrogenated under 20 psi of pressure of hydrogen at room temperature overnight. Filtration and concentration afforded crude of 5 as a brown oil (30 g, 100%).

Step 5: 2-(3,3-Difluorocyclohexyl)-4-phenylpyridine

To a solution of DAST (213 g, 1.325 mol) in 500 ml of dry DCM was added a solution of 5 (52 g, 0.207 mmol) in 500 ml of DCM at −70° C. After 1 hour, the reaction mixture was warmed to room temperature slowly, and stirred overnight. The reaction was quenched by adding water slowly at 0° C., neutralized with bicarbonate to pH=7-8, and extracted with DCM. The combined organic layers were washed with water and brine, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. Purification on silica gel afforded 6 as a yellow liquid (18 g, 32%).

Step 6: 2-(3,3-Difluorocyclohexyl)-1-methyl-4-phenylpyridinium iodide

A mixture of 6 (18 g, 66 mmol) and CH₃I (105 ml, 198 mmol) in CH₃COCH₃ (150 ml) in a retort was stirred at 90 degree for 2 days. After cooled to room temperature, the mixture was filtered. The filtered cake was washed with ethyl acetate to give 7 as a yellow solid (23 g, 85%).

Step 7: 2-(3,3-Difluorocyclohexyl)-1-methyl-4-phenylpiperidine

The suspension of 7 (1.3 g, 3.1 mmol) and PtO₂ (0.26 g) in 50 ml of MeOH was stirred under 1 atmosphere of hydrogen at room temperature overnight, and then filtered. The PtO₂ (0.13 g) was added again and the stirring was continued overnight more. After filtered and concentrated, the residue was dissolved in EA and washed with sat. bicarbonate sodium, water, brine, dried over sodium sulfate anhydrous. After filtered and concentrated, 8 (780 mg, 85%) was obtained as a brown oil.

Step 8: 2-(3,3-Difluorocyclohexyl)-4-phenylpiperidine-1-carbonitrile

To a solution of 8 (780 mg, 2.7 mmol) in 30 ml of CHCl₃ was added K₂CO₃ (1.3 g, 8.2 mmol) under nitrogen, followed by BrCN (430 mg, 4.1 mmol). The suspension was refluxed overnight. After cooled to room temperature, the reaction mixture was partitioned between DCM and water. The organic layer was washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. Purification on silica gel afforded 9 as off-white solid (480 mg, 56%).

Step 9: 2-(3,3-Difluorocyclohexyl)-4-phenylpiperidine

The suspension of 9 (480 mg, 1.6 mmol) in 30 ml of diluted aqueous HCl (1N) was refluxed overnight, and concentrated in vacuo. The residue was dissolved in ethyl acetate, washed with saturated aqueous NaHCO₃, water, brine, dried over sodium sulfate, filtered, and concentrated in vacuo to give 10 as a colorless oil (400 mg, 91%).

Step 10: Benzyl (2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidine-1-carboxylate

To a solution of 10 (4.1 g crude, 14.7 mmol) in 100 ml of THF and 50 ml of water was added sodium carbonate (3.9 g, 36.7 mmol), followed by CbzCl (5 g, 29.4 mmol) at room temperature. The reaction mixture was stirred at room temperature overnight, diluted with ethyl acetate, washed with water, brine, dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo. Purification on silica gel afforded benzyl 2-(3,3-difluorocyclohexyl)-4-phenylpiperidine-1-carboxylate as a mixture of 4 isomers (2.3 g, 38%). Chiral SFC separation afforded 500 mg of benzyl (2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidine-1-carboxylate 11.

Step 11: (2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidine

A suspension of 11 (500 mg, 1.2 mmol) and Pd(OH)₂ (0.2 g) in 10 ml of EtOH was hydrogenated under 1 atmosphere of hydrogen at room temperature overnight. Filtration and concentration afforded (2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidine as a colorless oil (330 mg, 98%).

Alternative Procedures for the Preparation of Intermediate II Step 1: tert-Butyl 2-(3-oxocyclohexyl)-4-phenylpiperidine-1-carboxylate

To a solution of compound 1 (10.8 g, 41.2 mmol) in Et₂O (150 mL) at −78° C. was added TMEDA (6.2 mL, 41.2 mmol), followed by sec-BuLi (41.4 mL, 1.3 eq, 53.8 mmol). The mixture was stirred at −78° C. for 2 h before a solution of CuCN.2LiCl (3.6 g, 20.6 mmol) in THF (41.2 mL) was added. The reaction mixture was allowed to stir at −50° C. for 1 h before a solution of compound 2 (4 g, 41.2 mmol) in TMSCl (26 mL, 206 mmol) was added. The reaction mixture was stirred at −50° C. for 30 min and then was allowed to stir at room temperature overnight. The reaction mixture was quenched with H₂O, stirred at room temperature briefly, diluted with EA, and filtered through Celite. The organic phase was separated, and the aqueous phase was extracted with EA (40 mL×4). The combined organic phases were washed with saturated NH4Cl (aq.), 5% NaHCO₃ (aq.), brine, and dried over a mixture of anhydrous Na₂SO₄ and K₂CO₃. Evaporation of the solvent in vacuo afforded the crude product which was purified by column chromatography to give 6.8 g of compound 3 in 46% yields.

¹H NMR (400 MHz, CDCl₃): δ 7.34 (t, J=7.2 Hz, 2H), 7.23 (t, J=7.2 Hz, 3H), 4.31˜4.35 (m, 1H), 4.15˜4.20 (m, 1H), 2.75˜3.0 (m, 2H), 2.25˜2.53 (m, 4H), 1.60˜2.25 (m, 8H), 1.25˜1.59 (m, 10H). LRMS (M+Na⁺): 380.

Step 2: 3-(4-Phenylpiperidin-2-yl)cyclohexanone

To a solution of 3 (6.27 g, 17.6 mmol) in MeOH (20 mL) was added HCl/MeOH (2 M, 40 mL). After 2 hours, the reaction mixture was concentrated to give 5.1 g of compound 4 as HCl salt in 100% yields.

LRMS (M+H⁺): 258.

Step 3: Benzyl 2-(3-oxocyclohexyl)-4-phenylpiperidine-1-carboxylate

To a solution of compound 4 (5.1 g, 17.6 mmol) in DCM (50 mL) were added Et₃N (5.3 g, 52.7 mmol) and CbzCl (4.5 g, 26.3 mmol) at 0° C. The mixture was allowed to stir at room temperature for 2 h, and quenched with H₂O, extracted with DCM (20 mL×3). The combined organics were washed with brine, dried over Na₂SO₄ and concentrated. The residue was purified by column chromatography to give 5.56 g of compound 5 in 81% yields.

¹H NMR (400 MHz, CDCl₃): δ 7.28˜7.39 (m, 7H), 7.15˜7.23 (m, 3H), 5.13˜5.19 (m, 2H), 3.95˜4.45 (m, 2H), 2.60˜3.20 (m, 2H), 1.59˜2.41 (m, 13H). LRMS (M+H⁺): 392.

Step 4: Benzyl (2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidine-1-carboxylate

To a solution of compound 5 (5.56 g, 14.2 mmol) in DCM (70 mL) was added dropwise DAST (4 eq, 56.8 mmol) at 0° C. The reaction mixture was stirred at room temperature for 12 h, poured slowly onto ice-water, extracted with DCM (20 mL×3). The combined organics were washed with NaHCO₃ (aq.) and brine, dried over Na₂SO₄, filtered, and concentrated. The residue was purified by p-HPLC to give 3.64 g of benzyl 2-(3,3-difluorocyclohexyl)-4-phenylpiperidine-1-carboxylate in 62% yields as a mixture of 4 isomers.

LRMS (M+H⁺): 414.

The mixture was resolved by SFC column to give benzyl (2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidine-1-carboxylate 6. (Column: Chiralcel OJ-H 250*4.6 mm I.D., Sum; Mobile phase: methanol (0.05% DEA) in CO₂ from 5% to 40%; Flow rate: 2.5 mL/min; Wavelength: 220 nm).

Step 5: (2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidine

A mixture of compound 6 (130 mg, 0.31 mmol) and Pd (OH)₂ (70 mg) in MeOH (20 mL) was stirred at 50° C. under H₂ (50 psi) for 4 hours. The mixture was filtrated and the filtrate was concentrated to give 80 mg of (2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidine 7 in 92% yields.

LRMS (M+H⁺): 280.

Intermediate III: 4-phenyl-2-(2,2,2-trifluoroethyl)piperidine

Step 1: 2-Chloro-4-phenylpyridine

To a mixture of 1 (57.36 g, 0.24 mol) in THF/H₂O (400 mL/100 mL) were added phenylboric acid (24.2 g, 0.2 mol) and K₂CO₃ (82.8 g, 0.6 mol). PdCl₂(dppf) (2 g) was then added after being charged with N₂ three times. The resulting mixture was refluxed for 2 hrs, cooled, and partitioned between a.q. NH₄Cl and EtOAc. The aqueous layer was washed with EtOAc. The combined organic layers were washed with water, brine and dried over Na₂SO₄. The solvent was removed in vacuo and the residue was purified by silica gel column (PE:EA=10:1) to afford 32 g of 2 (yield 84%).

Step 2: Methyl 4-phenylpyridine-2-carboxylate

To a solution of 2 (2 g, 0.01 mol) in MeOH (100 mL) were added TEA (5.33 g, 0.05 mol) and PdCl₂(dppf) (0.5 g). The reaction mixture was stirred overnight at 70° C. under 4 MPa CO. The suspension was filtered through a pad of celite and washed with MeOH. The combined filtrates were concentrated in vacuo. Purification on silica gel (PE:EA=10:1) afforded 1.5 g of 3 (yield 71%).

¹H-NMR (400 MHz, CDCl₃) δ 8.72 (d, 1H), 8.31 (m, 1H), 7.63 (m, 3H), 7.42 (m, 3H), 3.95 (s, 3H)

Step 3: (4-Phenylpyridin-2-yl)methanol

To a solution of 3 (1.5 g, 7 mmol) in THF (20 mL) was added LiAlH4 (0.32 g, 8.4 mmol). The reaction mixture was stirred at room temperature for 30 minutes, quenched by adding 15% NaOH aqueous solution, and filtered through silica gel. The filtrate was concentrated to give the crude product, which was used directly in the next step without further purification.

Step 4: 4-Phenylpyridine-2-carbaldehyde

To a solution of 4 (1.4 g, 7 mmol) in CH₂Cl₂ (100 mL) was added MnO₂ (1.8 g, 21 mmol). The mixture was refluxed overnight, cooled, and filtered through silica gel. The filtrate was concentrated in vacuo. Purification on silica gel (PE:EA=10:1) afforded 1.1 g of 5 (yield 78%).

¹H-NMR (400 MHz, CDCl₃) δ 10.14 (s, 1H), 8.82 (d, 1H), 8.18 (m, 1H), 7.64 (m, 3H), 7.45 (m, 3H)

Step 5: 2,2,2-Trifluoro-1-(4-phenylpyridin-2-yl)ethanol

To the solution of TMSCF₃ (245 mg, 2.5 mmol) in THF (50 mL) were added 5 (366 mg, 2 mmol) and TBAT (cat). The reaction mixture was stirred at room temperature for 1 hr before 1.0 N HCl (5 mL) was added. After 1 hr, the reaction mixture was partitioned between aqueous NaHCO₃ and EtOAc. The aqueous layer was washed with EtOAc. The combined organic layers were washed with water and brine, dried over Na₂SO₄, filtered, and concentrated in vacuo. The crude product thus obtained was used directly in the next step without further purification.

¹H-NMR (400 MHz, CDCl₃) δ 8.62 (d, 1H), 7.25-7.61 (m, 8H), 5.05 (m, 1H),

Step 6: 4-Phenyl-2-(2,2,2-trifluoroethyl)pyridine

A mixture of 6 (647 mg, 2.9 mmol), NaH (232 mg, 5.8 mmol, 60% in mineral oil), imidazole (26 mg, 0.3 mmol) in THF (30 mL) was stirred for a half an hour at room temperature before CS₂ (2 mL, 33.3 mmol) was introduced. After stirring for 1 h, iodomethane (0.3 mL, 4.8 mmol) was added. The resultant reaction mixture was stirred for another hour, poured into water (30 mL), extracted with EtOAc two times. The combined organic layers were washed with water and brine, dried over Na2SO4, filtered, and concentrated in vacuo to give a yellow oil. The residue was dissolved in toluene (30 mL), to which catalytic AIBN (100 mg) was added. The reaction mixture was refluxed under N₂ while a solution of Bu₃SnH (3 mL, 11 mmol) in toluene (3 mL) was added slowly over 30 minutes. After refluxing overnight, the reaction mixture was cooled, partitioned between saturated NaHCO₃ aqueous solution and EtOAc. The combined organic layers were washed with water and brine, dried over Na₂SO₄. The solvent was removed in vacuo and the residue was purified by silica gel column (PE:EA=20:1) to afford 0.32 g of 7 (yield 53%).

Step 7: 4-phenyl-2-(2,2,2-trifluoroethyl)piperidine

To a solution of 7 (300 mg, 1.23 mmol) in acetic acid (10 mL) was added Pd/C (100 mg). The reaction mixture was hydrogenated at 80° C. for 2 hrs. LC-MS showed the starting material was consumed. The suspension was filtered through a pad of celite and washed with methanol. The combined filtrates were concentrated in vacuo. The residue was partition between aqueous NaHCO₃ and EtOAc. The separated aqueous layer was washed with EtOAc. The combined organic layers were washed with water, brine and dried over Na₂SO₄. The solvent was removed in vacuo to afford 4-phenyl-2-(2,2,2-trifluoroethyl)piperidine 8.

Intermediate A to YY are depicted below in Table 1. Intermediates A to YY are either commercially available, or are taught in the literature.

TABLE 1 INTERMEDIATE STRUCTURE SOURCE A

Commercially available B

Commercially available C

Commercially available D

Commercially available E

Commercially available F

Commercially available G

Commercially available H

Commercially available I

Organic Letters (2005), 7(23), 5167-5170 J

Synlett (2007), (11), 1699-1702 K

Commercially available L

US 2005043309 M

J Heterocyclic Chemistry (2000), 37(1), 41-46 N

Commercially available O

Commercially available P

Synthesis 1983, 11, 902-903 Q

Synthesis 1983, 11, 902-903 R

Commercially available S

Commercially available T

J. Med. Chem., 1974, 17(9), 1020-1023 U

J. Org. Chem., (1985), 50(12), 2128- 2133 V

Commercially available W

Bulletin Chem Soc Japan (1999), 72(2), 303-311 X

Chem Communications (2007), 44: 4686-4688 Y

Commercially available Z

Commercially available AA

Heterocycles (1986), 24(9); 2011-2618. BB

Indian Journmal of Chem., Section B: Organic Chemistry (1985), 24B(6), 659-661. CC

J. Labelled Compounds and Radiopharma- ceuticals (1990), 28(1), 15-24. DD

WO 2005/005438 EE

J. Heterocyclic Chem. (1975), 9(1), 44-48. FF

Tetrahedron Letters (1986), 27(10), 1127-1130. GG

Eur. J. Med. Chem. (2000), 39(9), 815-823. HH

J. Org. Chem. (1990), 55(16), 4789-4791. II

U.S. Pat. No. 4,952,694 JJ

J. Chem. Soc. Perkin Trans. (1985), (2), 213-219. KK

U.S. Pat. No. 3,998,331 LL

Arch. Pharma. (1985), 318(10), 871-878. MM

J. Med Chem. (1977), 20(5), 718-721. NN

J. Heterocyclic Chem., 1983, 649. OO

WO 2006/047017 PP

Heterocycles, 1997, 129. QQ

J. Am. Chem. Soc. (1985), 107(17), 4998-4999. RR

J. Am. Chem. Soc. (1985), 107(17), 4998-4999. SS

Heterocycles (1995), 41(1), 29- 36. TT

J. Prak. Chemie (1999), 341(5), 487-491. UU

J. Med. Chem. (1990), 33(11), 3028-3034.. VV

Commercially available WW

WO 98/00134 XX

Commercially available YY

J. Org. Chem. (2002), 67(11), 3972-3974.

EXAMPLE 1 4′-[(4-phenylpiperidin-1-yl)carbonyl]-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]

Step 1: Ethyl(2E)-3,4-dihydronaphthalen-1(2H)-ylideneacetate

Sodium hydride (2.160 g, 54.0 mmol) in THF (150 ml) was added triethyl phosphonoacetate (10.81 ml, 54.0 mmol) dropwise. Stir at room temperature for 1 hour, added a-tetralone (3.99 ml, 30 mmol) and heated overnight at 70° C. The next day the solution was cooled to room temperature and quenched with 1N HCl. Extracted three times with EtOAc and washed the combined organics with brine. The organics were dried over sodium sulfate, concentrated, and purified on silica gel 10% EtOAc/Hex.

¹H NMR (CDCl₃) δ 7.65 (d, J=7.9 Hz, 1H), 7.27-7.13 (m, 3H), 6.33 (t, J=1.8 Hz, 1H), 4.20 (q, J=7.1 Hz, 2H), 3.22-3.17 (m, 2H), 2.80 (t, J=6.2 Hz, 2H), 1.88-1.83 (m, 2H), 1.32 (t, J=7.1 Hz, 3H). LRMS (M+H)=217.10

Step 2: Ethyl 1′-benzyl-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylate

N-benzyl-N-(methoxymethyl)-N-trimethylsilylmethylamine (2.112 ml, 8.26 mmol) and ethyl(2E)-3,4-dihydronaphthalen-1(2H)-ylideneacetate (1.785 g, 8.26 mmol) in CH₂Cl₂ (33.3 ml) at 0° C. was added TFA (0.064 ml, 0.826 mmol) dropwise. Removed the ice bath and stirred at room temperature for 4 hours. Dilute with CH₂Cl₂ and wash twice with saturated NaHCO₃. The organics were dried over sodium sulfate, concentrated, and purified on silica gel 20% EtOAc/Hex.

¹H NMR (CDCl₃) δ 7.76-7.68 (m, 1H), 7.41-7.18 (m, 6H), 7.15-7.09 (m, 1H), 7.06-6.98 (m, 1H), 4.12-4.03 (m, 2H), 3.75-3.63 (m, 2H), 3.42-3.36 (m, 1H), 3.20-3.10 (m, 1H), 3.07-2.90 (m, 2H), 2.78-2.67 (m, 2H), 2.63-2.57 (m, 1H), 1.89-1.81 (m, 2H), 1.69-1.62 (m, 2H), 1.20-1.09 (m, 3H).

LRMS (M+H)=350.20

Step 3: 1′-benzyl-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylic acid

Ethyl 1′-benzyl-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylate (1.1 g, 3.15 mmol) in THF/MeOH/H2O (41 ml) was added 2N sodium hydroxide (4.72 ml, 9.44 mmol). Stir overnight at 50° C. Cooled to room temperature and acidified to pH1-2 with 0.5N HCl and extracted with EtOAc. The organic layer was dried and concentrated. The crude acid was not purified.

¹H NMR (CDCl₃) δ 7.36-7.22 (m, 6H), 7.11-6.92 (m, 3H), 3.73-3.65 (m, 2H), 3.18-3.11 (m, 2H), 3.00-2.49 (m, 6H), 1.89-1.55 (m, 3H). LRMS (M+H)=322.08

Step 4: N-benzyl-4′-[(4-phenylpiperidin-1-yl)carbonyl]-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]

N-benzyl-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylic acid (0.1 g, 0.311 mmol) in CH₂Cl₂ (4 ml) was added oxalyl chloride (0.187 ml, 0.373 mmol) followed by 2 drops of DMF. Stirred at room temperature for 30 minutes and concentrated. Dissolve in THF (5 mL) and added 4-phenylpiperidine (0.050 g, 0.311 mmol) and triethylamine (0.173 ml, 1.245 mmol).

The solution was stirred for 2 hours then concentrated, taken up in CH₂Cl₂ and washed with water. The crude product was not purified.

¹H NMR (CDCl₃) δ 7.86-7.78 (m, 1H), 7.40-7.35 (m, 2H), 7.31-7.16 (m, 7H), 7.10-7.03 (m, 3H), 7.00-6.95 (m, 1H), 4.88-4.73 (m, 1H), 3.72-3.55 (m, 4H), 3.29-3.08 (m, 5H), 2.76-2.69 (m, 3H), 2.60-2.39 (m, 4H), 2.10-2.02 (m, 1H), 1.80-1.60 (m, 4H). LRMS (M+H)=465.22

Step 5: 4′-[(4-phenylpiperidin-1-yl)carbonyl]-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]

N-benzyl-4′-[(4-phenylpiperidin-1-yl)carbonyl]-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine] (0.15 g, 0.323 mmol) in EtOH (20 ml) was added Pearlman's Catalyst (0.075 g, 0.107 mmol) and hydrogenated with a balloon for 2 hours. Filtered through celite and concentrated.

The product was purified on the Waters Prep HPLC. The desired fractions were free based with NaHCO₃ and extracted 2× with EtOAc.

¹H NMR (CD₃OD) δ 7.67-7.54 (m, 1H), 7.30-7.08 (m, 6H), 6.96-6.91 (m, 2H), 4.66-4.57 (m, 1H), 4.17-3.98 (m, 2H), 3.72-3.64 (m, 1H), 3.58-3.50 (m, 3H), 2.91-2.73 (m, 3H), 2.65-2.39 (m, 2H), 2.19-2.12 (m, 1H), 2.00-1.60 (m, 5H), 1.53-1.47 (m, 1H), 1.40-1.05 (m, 2H). LRMS (M+H)=375.13

EXAMPLE 2 [(1R,4′S)-6-methyl-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidin]-4′-yl](4-phenylpiperidin-1-yl)methanone

Step 1: 6-bromo-3,4-dihydronaphthalen-1(2H)-one

To a suspension of 6-amino-3,4-dihydro-2H-naphthalen-1-one (20.5 g, 127 mmol) in 25% HBr (aq) (1017 ml) at 0° C. was added a solution of sodium nitrite (10.53 g, 153 mmol) in water (50 ml) dropwise at a rate as to maintain the temperature below 3°. The cooled reaction mixture was then added to a cooled solution of copper(I) bromide (18.79 g, 131 mmol) in HBr (98 ml, 865 mmol). When the addition was done, the reaction mixture was stirred at 0° C. for 1 h, then warmed to rt. Water (380 mL) was added and the product was extracted with a mixture of Et₂O/EtOAc (8:2, 3×). The organic layer was dried over Na₂SO₄, filtered, and concentrated in vacuo to give a dark brown crude oil. The crude was purified by distillation (3 mm Hg) to give 16.415 g of 6-bromo-3,4-dihydro-2H-naphthalen-1-one.

¹H NMR (CDCl₃): δ 7.89 (d, J=8.6 Hz, 1H); 7.44 (d, J=6.8 Hz, 2H); 2.94 (t, J=6.1 Hz, 2H); 2.65 (t, J=6.5 Hz, 2H); 2.14 (t, J=6.4 Hz, 2H). LRMS (M+H)=226.8

Step 2: Ethyl (2E)-(6-bromo-3,4-dihydronaphthalen-1(2H)-ylidene)ethanoate

To a suspension of NaH (2.73 g, 68.4 mmol in THF (190 ml) at room temperature was added triethyl phosphonoacetate (31.3 ml, 157 mmol) dropwise. The resulting solution was stirred at room temperature for 1 h. Then 6-bromo-3,4-dihydronaphthalen-1(2H)-one (19.5839 g, 87 mmol) was added in one portion and the reaction mixture stirred overnight. The reaction mixture was quenched with 1N HCl to pH˜1. The mixture was extracted three times with EtOAc. The combined organic layers were dried over Na₂SO₄, filtered, and concentrated in vacuo to give an orange crude oil. The crude was purified on silica gel (8% EtOAc/hexanes) affording 6.7 g of Ethyl (2E)-(6-bromo-3,4-dihydronaphthalen-1(2H)-ylidene)ethanoate.

¹H NMR (CDCl₃): δ 7.53-7.46 (m, 1H); 7.32 (d, J=6.6 Hz, 2H); 6.30 (s, 1H); 4.20 (q, J=7.1 Hz, 2H); 3.19-3.12 (m, 2H); 2.77 (t, J=6.2 Hz, 2H); 1.84 (p, J=6.3 Hz, 2H); 1.31 (t, J=7.1 Hz, 3H). LRMS (M+H)=296.74

Step 3: Ethyl (1R,4′S)-1′-benzyl-6-bromo-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylate

To a solution of N-(methoxymethyl)-N-(trimethylsilylmethyl)benzylamine (6.85 ml, 26.8 mmol) and [6-Bromo-3,4-dihydro-2H-naphthalen-(E)-ylidene]-acetic acid ethyl ester (7.9 g, 26.8 mmol) in CH₂Cl₂ (14.33 ml) at 0° C. was added TFA (0.206 ml, 2.68 mmol) dropwise. The ice bath was removed and the reaction mixture was stirred at room temperature. The process of the reaction was followed by LC/MS. N-(methoxymethyl)-N-(trimethylsilylmethyl)benzylamine (6.85 ml, 26.8 mmol) was added after every 2 h and stirred at room temperature till LC/MS showed no SM. The solution was diluted with CH₂Cl₂, washed three times with saturated aqueous NaHCO₃, dried, filtered, concentrated, and purified on silica gel (10% EtOAc/hexanes) affording 8.85 g of ethyl (1R,4′S)-1′-benzyl-6-bromo-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylate.

¹H NMR (CDCl₃): δ 7.59 (d, J=8.5 Hz, 1H); 7.33-7.22 (m, 5H); 7.22-7.15 (m, 1H); 7.13 (s, 1H); 4.04 (q, J=7.1 Hz, 2H); 3.72-3.58 (m, 2H); 3.33-3.23 (m, 1H); 3.17-3.07 (m, 1H); 2.98-2.88 (m, 1H); 2.86 (d, J=9.2 Hz, 1H); 2.74-2.53 (m, 2H); 2.51 (d, J=9.2 Hz, 1H); 1.81-1.75 (m, 2H); 1.74-1.53 (m, 2H); 1.13 (t, J=7.1 Hz, 3H). LRMS (M+H)=429.72

Step 4: 1′-tert-butyl 4′-ethyl (1R,4′S)-6-bromo-3,4-dihydro-1′H,2H-spiro[naphthalene-1,3′-pyrrolidine]-1′,4′-dicarboxylate

To a solution of ethyl (1R,4′S)-1′-benzyl-6-bromo-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylate (8.85 g, 20.66 mmol) at 0° C. was added 1-chloroethyl chloroformate (2.68 ml, 24.79 mmol) dropwise. The reaction mixture was stirred at 0° C. for 15 minutes, warmed to room temperature then heated to 40° C. for 2 hours. The reaction was cooled to room temperature concentrated in vacuo. The residue was dissolved in MeOH (275 ml) and heated to reflux for 1 hour. The crude amine was cooled to room temperature, concentrated in vacuo, and reconstituted in THF (207 ml). Boc₂O (4.96 g, 22.73 mmol) was added to the solution followed by DIPEA (7.22 ml, 41.3 mmol). The reaction mixture was stirred at room temperature overnight. The solution concentrated, dissolved in CH₂Cl₂ and washed with water. The organic was dried, filtered, concentrated, and purified on silica gel (15% EtOAc/hexanes) affording 7.1 g of 1′-tert-butyl 4′-ethyl (1R,4′S)-6-bromo-3,4-dihydro-1′H,2H-spiro[naphthalene-1,3′-pyrrolidine]-1′,4′-dicarboxylate.

¹H NMR (CDCl₃): δ 7.31 (dd, J=8.5, 2.1 Hz, 1H); 7.26-7.18 (m, 2H); 4.14-4.05 (m, 2H); 3.95 (ddd, J=15.1, 10.8, 7.1 Hz, 1H); 3.81-3.68 (m, 3H); 3.61 (d, J=11.1 Hz, 1H); 3.47-3.32 (m, 2H); 2.75-2.68 (m, 2H); 1.91-1.77 (m, 2H); 1.76-1.57 (m, 2H); 1.48 (d, J=12.1 Hz, 9H); 1.05 (dt, J=14.7, 7.1 Hz, 3H). LRMS (M+H)=439.74

Step 5: (1R,4′S)-6-bromo-1′-(tert-butoxycarbonyl)-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylic acid

To a solution of 1′-tert-butyl 4′-ethyl (1R,4′S)-6-bromo-3,4-dihydro-1′H,2H-spiro[naphthalene-1,3′-pyrrolidine]-1′,4′-dicarboxylate (7.1 g, 16.20 mmol) in THF/MeOH/H2O (3:1:1, 40.5 ml) at room temperature was added sodium hydroxide (3M, 16.20 ml, 48.6 mmol) in one portion. The reaction mixture was heated to 55° C. and stirred for 2 hours. The solution was cooled to room temperature, neutralized with 2N HCl, and concentrated to dryness. The residue was diluted with MeOH/chloroform (1:9) and filtered to remove the salt. The filtrate was concentrated to give 6.55 g of crude (1R,4′S)-6-bromo-1′-(tert-butoxycarbonyl)-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylic acid. The crude was not purified.

¹H NMR (399 MHz, CD 30D): δ 7.42-7.28 (m, 3H); 3.76-3.57 (m, 5H); 2.80-2.74 (m, 3H); 1.93 (s, 1H); 1.79-1.68 (m, 4H); 1.48 (d, J=13.4 Hz, 9H). LRMS (M+H)=411.72

Step 6: tert-butyl (1R,4′S)-6-bromo-4′-[(4-phenylpiperidin-1-yl)carbonyl]-3,4-dihydro-1′H,2H-spiro[naphthalene-1,3′-pyrrolidine]-1′-carboxylate

To a solution of (1R,4′S)-6-bromo-1′-(tert-butoxycarbonyl)-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidine]-4′-carboxylic acid (1.5 g, 3.66 mmol), 4-phenylpiperidine (0.589 g, 3.66 mmol), and BOP (2.425 g, 5.48 mmol) in CH₂Cl₂ (73 ml) at room temperature was added DIPEA (0.207 ml, 1.187 mmol) in one portion. The reaction mixture was stirred for 15 hours. The solution was diluted with CH₂Cl₂, washed with water (1×), brine (1×), dried, filtered, concentrated, and purified on silica gel (10%-50% EtOAc/hexanes) affording 1.3 g tert-butyl (1R,4′S)-6-bromo-4′-[(4-phenylpiperidin-1-yl)carbonyl]-3,4-dihydro-1′H,2H-spiro[naphthalene-1,3′-pyrrolidine]-1′-carboxylate.

¹H NMR (CDCl₃): δ 7.31 (t, J=14.4 Hz, 5H); 7.24-7.16 (m, 1H); 7.12 (s, 1H); 6.98 (d, J=7.2 Hz, 1H); 4.73 (d, J=13.1 Hz, 1H); 4.07 (d, J=10.2 Hz, 1H); 3.71 (d, J=13.9 Hz, 2H); 3.67-3.51 (m, 3H); 2.73 (s, 2H); 2.52 (s, 2H); 1.83 (d, J=13.6 Hz, 1H); 1.72 (s, 4H); 1.47 (d, J=7.8 Hz, 9H); 1.17 (t, J=12.9 Hz, 1H). LRMS (M+H)=554.87

Step 7: [(1R,4′S)-6-methyl-3,4-dihydro-2H-spiro[naphthalene-1,3′-pyrrolidin]-4′-yl](4-phenylpiperidin-1-yl)methanone

To a microwave tube equipped with a stir bar was added Pd(Ph₃P)₄ (94 mg, 0.081 mmol) and potassium carbonate (164 mg, 1.185 mmol). The tube was flushed with argon. Then trimethylboroxine (0.028 ml, 0.203 mmol) was added followed by tert-butyl (1R,4′S)-6-bromo-4′-[(4-phenylpiperidin-1-yl)carbonyl]-3,4-dihydro-1′H,2H-spiro[naphthalene-1,3′-pyrrolidine]-1′-carboxylate (100 mg, 0.181 mmol) in DMF (0.9 ml). The reaction mixture was heated to 105° C. under N₂ for 15 hours. The mixture was cooled to room temperature, and filtered through Celite. The wet cake was washed several times with EtOAc. The combined organics were washed once with water and brine, dried, filtered, concentrated. The crude was dissolved in CH₂Cl₂ (20 ml). QuadraPure TU (1 g) was added and the mixture was stirred at 35° C. for 16 hours. The mixture was filtered through Celite and the wet cake was washed several times with CH₂Cl₂. The combined organics were concentrated and purified by reverse phase HPLC. The desired fractions were free based with 1N NaOH and extracted three times with CH₂Cl₂. The residue was dissolved in CH₂Cl₂. TFA was added and the reaction was stirred at room temperature for 1 hour. The solution was concentrated, basified with 1N NaOH, and extracted three times with CH₂Cl₂. The combined organics were dried, filtered, and concentrated to give the free amine.

¹H NMR (399 MHz, CDCl₃): δ 7.36 (d, J=8.1 Hz, 1H); 7.21 (t, J=7.9 Hz, 3H); 7.12 (d, J=7.5 Hz, 1H); 7.04 (d, J=7.2 Hz, 2H); 6.88 (s, 1H); 4.78 (t, J=15.1 Hz, 1H); 3.81 (dd, J=11.7, 5.6 Hz, 1H); 3.67-3.58 (m, 1H); 3.51-3.25 (m, 2H); 3.27-3.13 (m, 1H); 3.05 (d, J=12.0 Hz, 1H); 2.76-2.68 (m, 2H); 2.65-2.49 (m, 4H); 2.26 (d, J=20.3 Hz, 3H); 1.95-1.53 (m, 6H); 1.43 (td, J=12.7, 4.1 Hz, 1H); 1.14 (s, 1H). LRMS (M+H)=388.90

EXAMPLE 3 [(4R,4′S)-8-methoxy-2,3-dihydrospiro[chromene-4,3′-pyrrolidin]-4′-yl][(2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidin-1-yl]methanone

Step 1: 1-Methoxy-2-(methoxymethoxy)benzene

To a mixture of compound 1 (50 g, 0.4 mol) in DCM (500 mL) were added MOMCl (38.64 g, 0.48 mol) and DIEA (77.4 g, 0.6 mol) at 0° C. The mixture was stirred at room temperature overnight, diluted with EtOAc, and washed with 1N HCl solution. The organic layer were washed with brine, dried over Na₂SO₄, filtered, and concentrated in vacuo. Purification on silica gel (PE:EA=20:1) gave 64 g of compound 2 in 99% yields.

¹H NMR CDCl₃ (400 MHz, CDCl₃): δ 7.12 (d, J=8.0 Hz, 1H), 6.95 (d, J=8.0 Hz, 1H), 6.82 (t, J=8.0 Hz, 2H), 5.21 (s, 2H), 3.86 (s, 3H), 3.5 (s, 3H).

Step 2: 1-Iodo-3-methoxy-2-(methoxymethoxy)benzene

To a mixture of compound 2 (48 g, 0.29 mol) in THF (600 mL) was added n-BuLi (197 mL, 1.6 M) at −78° C. After 2 h, a solution of I₂ (40 g, 0.16 mol) in THF (200 mL) was added dropwise at −50° C. The reaction mixture was stirred at room temperature overnight, quenched by NH₄Cl and Na₂S₂O₅ solutions at 0° C., and extracted with EA. The combined extracts were washed with brine, dried over Na₂SO₄ and then purified on silica gel (PE:EA=60:1) to give 64 g of compound 3 in 50% yields.

¹H NMR (400 MHz, CDCl₃): δ 7.28˜7.36 (m, 1H), 7.06˜7.12 (m, 1H), 6.68˜6.76 (m, 1H), 5.16 (s, 2H), 3.82 (s, 3H), 3.46 (s, 3H).

Step 3: 2-Iodo-6-methoxyphenol

To a mixture of compound 3 (52 g, 0.18 mol) in MeOH (400 mL) was added HCl/MeOH (100 mL, 2 M) at 0° C. The reaction mixture was stirred at RT for 4 h, then concentrated to give 42 g of compound 4 in 95% yields.

¹H NMR (400 MHz, CDCl₃): δ 7.12 (d, J=8.0 Hz, 1H), 6.70 (d, J=8.0 Hz, 1H), 6.65 (t, J=8.0 Hz, 1H), 4.46 (s, 1H), 3.75 (s, 3H).

Step 4: 3-(2-Iodo-6-methoxyphenoxy)propan-1-ol

A mixture of compound 4 (40 g, 0.16 mol), Br(CH₂)₃OH (33.3 g, 0.24 mol) and Cs₂CO₃ (104.3 g, 0.32 mol) in DMF (200 mL) was stirred at room temperature overnight, then diluted with water. The resulting mixture was extracted with EA. The combined extracts were washed with brine, dried over Na₂SO₄ and then purified on silica gel (PE:EA=30:1) to give 48 g of compound 5 in 60% yields.

¹H NMR (400 MHz, CDCl₃): δ 7.20˜7.23 (m, 1H), 6.75˜6.78 (m, 1H), 6.68˜6.72 (m, 1H), 3.98˜4.01 (m, 2H), 3.80˜3.83 (m, 2H), 3.40˜3.44 (m, 2H), 1.90˜1.93 (m, 3H).

Step 5: 3-(2-Iodo-6-methoxyphenoxy)propanal

To a solution of compound 5 (48 g, 0.16 mol) in DCM (500 mL) at 0° C. were added Py.SO₃ (50.9 g, 0.32 mol), DIEA (51.6 g, 0.4 mol) and DMSO (18.72 g, 0.24 mol). The mixture was stirred at 0° C. for 1 h and then quenched by water, extracted with EA. The combined extracts were dried over Na₂SO₄ and filtered. The filtrate was concentrated to give 48 g of compound 6. It was used directly in the next step without further purification.

Step 6: Ethyl (2E)-5-(2-iodo-6-methoxyphenoxy)pent-2-enoate

To a solution of ethyl 2-(diethoxyphosphoryl)acetate (62.7 g, 0.28 mol) in THF (500 mL) at 0° C. was added NaH (6.77 g, 0.28 mol). After stirring for 1 h, a solution of compound 6 (48 g, 0.16 mol) in THF was added dropwise. The mixture was stirred at room temperature overnight, quenched with water, and extracted with EA. The combined extracts were dried over Na₂SO₄ and filtered. The filtrate was concentrated and purified on silica gel (PE:EA=30:1) to give 13 g of compound 7 in 30% yields.

¹H NMR (400 MHz, CDCl₃): δ 7.25˜7.28 (m, 1H), 7.03˜7.07 (m, 1H), 6.78˜6.82 (m, 1H), 6.70˜6.75 (m, 1H), 5.9˜5.97 (m, 1H), 4.10˜4.15 (m, 2H), 4.00˜4.05 (m, 2H), 3.75˜3.78 (m, 3H), 2.64˜2.70 (m, 2H), 1.53 (s, 3H). LRMS (M+H⁺): 377.

Step 7: Ethyl (2E)-(8-methoxy-2,3-dihydro-4H-chromen-4-ylidene)ethanoate

A mixture of compound 7 (12 g, 0.032 mol), Ag₂CO₃ (17.6 g, 0.064 mmol), Pd(AcO)₂ (2.5 g, 0.016 mmol) and PPh₃ (8.416 g, 0.032 mmol) in toluene (200 mL) was refluxed overnight, filtered, and concentrated in vacuo. Purification on silica gel (PE:EA=30:1) gave 3 g of compound 8 in 39% yields.

¹H NMR (400 MHz, CDCl₃): δ 7.09˜7.11 (m, 1H), 6.76˜6.82 (m, 1H), 6.28 (s, 1H), 4.22˜4.24 (m, 2H), 4.10˜4.13 (m, 2H), 3.81 (s, 3H), 3.33 (s, 3H), 1.24˜1.26 (m, 3H). LRMS (M+H⁺): 249.

Step 8: Ethyl (1R,4′S)-8-methoxy-1′-benzyl-2,3-dihydrospiro[chromene-4,3′-pyrrolidine]-4′-carboxylate

To a mixture of compound 8 (3 g, 12 mmol) and N-benzyl-N-(methoxymethyl)-N-trimethylsilylmethylamine (8.5 g, 36 mmol) in DCM (5 mL) at 0° C. was added TFA (0.136 g, 1 M in DCM). The mixture was stirred at room temperature overnight, and washed with NaHCO₃ solution. The organic layer was dried over Na₂SO₄, filtered, and concentrated in vacuo. Purification on silica gel (PE:EA=50:1 to 10:1) gave 4.5 g of compound 9 in 99% yields.

¹H (400 MHz, CDCl₃): δ 7.20˜7.22 (m, 5H), 6.86˜6.88 (m, 1H), 6.70˜6.74 (m, 1H), 6.61˜6.64 (m, 1H), 4.50˜4.53 (m, 2H), 4.00˜4.03 (m, 2H), 3.84 (s, 3H), 3.69 (s, 2H), 3.32 (s, 2H), 2.95 (t, J=12.0 Hz, 2H), 2.61 (d, J=8.0 Hz, 1H), 1.90 (s, 2H), 1.10˜1.14 (m, 3H).

LRMS (M+H⁺): 382

Step 9: 1′-tert-Butyl 4′-ethyl (4R,4′S)-8-methoxy-1′-benzyl-2,3-dihydrospiro[chromene-4,3′-pyrrolidine]-1′,4′-dicarboxylate

To a mixture of compound 9 (4.5 g, 11.8 mmol) in EtOH (400 mL) was added Pd/C (450 mg) and Boc₂O (10 g, 70.8 mmol). The mixture was stirred at 50° C. under H₂ (50 Psi) overnight, and then filtered. The filtrate was purified on silica gel to give 4.5 g of compound 10 in 95% yields.

¹H (400 MHz, CDCl₃): δ 6.86 (d, J=8.0 Hz, 2H), 6.74 (d, J=8.0 Hz, 1H), 4.10˜4.14 (m, 2H), 3.90˜4.93 (m, 2H), 3.85 (s, 3H), 3.6˜3.64 (m, 2H), 3.4˜3.5 (m, 2H), 2.82˜2.85 (m, 1H), 1.80˜1.85 (m, 2H), 1.43 (s, 9H), 1.00˜1.03 (m, 3H). LRMS (M+H⁺): 391

Step 10: (1R,4′S)-8-Methoxy-1′-(tert-butoxycarbonyl)-2,3-dihydrospiro[chromene-4,3′-pyrrolidine]-4′-carboxylic acid

A mixture of compound 10 (1 g, 2.56 mmol) in NaOH/MeOH (20 mL, 2 M) was stirred at room temperature for 3 h. The mixture was acidified to pH 2˜3 with 2M HCl and extracted to times with CH₂Cl₂. The combined organic layers were dried over Na₂SO₄ and concentrated to give 0.85 g of compound 11 in 91% yields.

LRMS (M+H⁺): 364.

Step 11: [(4R,4′S)-8-methoxy-1′-(tert-butoxycarbonyl)-2,3-dihydrospiro[chromene-4,3′-pyrrolidin]-4′-yl][(2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidin-1-yl]methanone

A solution of compound 11 (100 mg, 0.275 mmol), (2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidine (77 mg, 0.275 mmol), HATU (171 mg, 0.45 mmol) and DIEA (71 mg, 0.6 mmol) in DMF were stirred at room temperature overnight, diluted with EA, and washed with water. The organic layer was dried over Na₂SO₄, filtered, and concentrated in vacuo. Purification on silica gel gave 70 mg of compound 12 in 41% yields.

LRMS (M+H⁺): 625.

Step 12: [(4R,4′S)-8-methoxy-2,3-dihydrospiro[chromene-4,3′-pyrrolidin]-4′-yl][(2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidin-1-yl]methanone

To a solution of compound 12 (70 mg) in 2 mL of MeOH was added a solution of HCl/MeOH (2 mL, 2 M). After 2 h at room temperature, the mixture was concentrated in vacuo to give [(4R,4′S)-8-methoxy-2,3-dihydrospiro[chromene-4,3′-pyrrolidin]-4′-yl][(2S,4R)-2-(3,3-difluorocyclohexyl)-4-phenylpiperidin-1-yl]methanone as HCl salts.

1H NMR (400 MHz, methanol-d₄) δ 7.08 (d, J=7.6 Hz, 1H, Ar—H), 6.99 (t, J=7.2 Hz, 2H, Ar—H), 6.89 (d, J=7.2 Hz, 1H, Ar—H), 6.76 (d, J=7.2 Hz, 1H, Ar—H), 6.74 (m, 1H, Ar—H), 6.73 (d, J=8.0 Hz, 1H, Ar—H), 4.08 (m, 3H, CH), 3.77 (m, 2H, CH), 3.58 (m, 2H, CH), 3.45 (s, 3H, OCH₃), 3.26 (m, 2H, CH), 2.93 (m, 1H, CH), 2.25 (m, 1H, CH), 1.89 (m, 2H, CH), 1.77 (m, 4H, CH), 1.60 (m, 1H, CH), 1.52 (m, 1H, CH), 1.44 (m, 4H, CH), 1.31 (m, 1H, CH), 0.91 (m, 3H, CH), 0.10 (m, 1H, CH). LRMS (M+H⁺): 525.

EXAMPLES 4-137

The following compounds were prepared similar to Examples 1 and 2 using the starting materials and methods described herein, and applying the knowledge of one of skilled in the art.

TABLE 2 Parent Ex Scheme Product Name MW 4 1

(1R,4′S)-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′-yl(4- phenylpiperidin-1- yl)methanone 360.504 5 1

(1R,4′S)-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′- yl[(2S,4R)-4-phenyl-2- (propan-2-yl)piperidin- 1-yl]methanone 402.585 6 1

(1R,4′S)-3,4-dihydro- 2H-spiro[naphthalene- 1,3′-pyrrolidin]-4′-yl(4- phenylpiperidin-1- yl)methanone 374.531 7 1

(1R,4′S)-3,4-dihydro- 2H-spiro[naphthalene- 1,3′-pyrrolidin]-4′- yl[(2S,4R)-4-phenyl-2- (propan-2-yl)piperidin- 1-yl]methanone 416.612 8 1

(4R,4′S)-2,3- dihydrospiro[chromene- 4,3′-pyrrolidin]-4′-yl(4- phenylpiperidin-1- yl)methanone 376.503 9 1

(1R,4′S)-3,4-dihydro- 2H-spiro[naphthalene- 1,3′-pyrrolidin]-4′- yl[(2S,4R)-2,4- diphenylpiperidin-1- yl]methanone 450.629 10 1

(1S,4′S)-3,4-dihydro- 2H-spiro[naphthalene- 1,3′-pyrrolidin]-4′-yl[2- (2-methoxypropan-2- yl)piperidin-1-yl] methanone 370.54 11 1

[(1R,4′S)-4,4-dimethyl- 3,4-dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 402.585 12 1

[(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1- yl][(1R,4′S)-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl] methanone 456.677 13 1

[(2R,4S)-2-cyclohexyl- 4-phenylpiperidin-1- yl][(1R,4′S)-3,4- dihydro-2H- spiro[naphthalene-1,3′- pyrrolidin]-4′-yl] methanone 456.677 14 2

[(1R,4′S)-7-bromo-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 453.427 15 1

(1S,4′S)-3,4-dihydro- 2H-spiro[naphthalene- 1,3′-pyrrolidin]-4′-yl[2- (3-methoxypentan-3- yl)piperidin-1-yl] methanone 398.594 16 1

[(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1- yl][(1R,4′S)-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′-yl] methanone 442.65 17 2

[(1R,4′S)-6-bromo-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1- yl)methanone 453.427 18 1

[(1R,4′S)-6-methoxy- 3,4-dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 404.557 19 2

[(1R,4′S)-6-chloro-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 408.976 20 2

[(1R,4′S)-6-bromo-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](1′H- spiro[indene-1,4'- piperidin]-1′-yl) methanone 477.449 21 1

(1R,4′S)-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′- yl[(2S,4R)-2,4- diphenylpiperidin-1-yl] methanone 436.602 22 2

[(1R,4′S)-6-bromo-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′- yl][(2S,4R)-2,4- diphenylpiperidin-1-yl] methanone 529.525 23 1

(1S,4′S)-3,4-dihydro- 2H-spiro[naphthalene- 1,3′-pyrrolidin]-4′-yl(4- phenylpiperidin-1-yl) methanone 374.531 24 1

(3R,4S)-2′,3′-dihydro- 1′H-spiro[pyrrolidine- 3,4'-quinolin]-4-yl(4- phenylpiperidin-1-yl) methanone 375.518 25 2

[(1R,4′S)-6-bromo-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl] [(2S,4R)-4-phenyl-2- (propan-2-yl)piperidin- 1-yl]methanone 495.508 26 1

[(1R,4′S)-6-hydroxy- 3,4-dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 390.53 27 2

[(1R,4′S)-5-bromo-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 453.427 28 1

[(1R,4′S)-6-fluoro-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 392.521 29 1

(3R,4S)-7′,8′-dihydro- 6′H-spiro[pyrrolidine- 3,5′-quinolin]-4-yl(4- phenylpiperidin-1-yl) methanone 375.518 30 2

[(1R,4′S)-5-bromo-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 439.4 31 2

(4-phenylpiperidin-1- yl)[(1R,4′S)-5-(propan- 2-yl)-3,4-dihydro-2H- spiro[naphthalene-1,3′- pyrrolidin]-4′-yl] methanone 416.612 32 2

[(1R,4′S)-6-bromo-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl] [(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1-yl] methanone 535.573 33 2

[(1R,4′S)-6-bromo-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl] [(2R,4S)-2-cyclohexyl- 4-phenylpiperidin-1-yl] methanone 535.573 34 1

[(3R,4S)-1′- (methylsulfonyl)-2′,3′- dihydro-1′H-spiro [pyrrolidine-3,4′- quinolin]-4-yl](4- phenylpiperidin-1-yl) methanone 453.608 35 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](4- phenylpiperidin-1-yl) methanone 409.963 36 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl][(2S,4R)- 4-phenyl-2-(propan-2- yl)piperidin-1- yl]methanone 452.045 37 2

[(3R,4S)-2′-bromo-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](4- phenylpiperidin-1-yl) methanone 454.414 38 1

(3R,4S)-2′,3′- dihydrospiro[pyrrolidine- 3,4′-thiochromen]-4- yl(4-phenylpiperidin-1- yl)methanone 392.568 39 2

[(3R,4S)-2′- (dimethylamino)-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](4- phenylpiperidin-1-yl) methanone 418.587 40 2

[(3R,4S)-2′- (methylamino)-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](4- phenylpiperidin-1-yl) methanone 404.56 41 2

[(1R,4′S)-6-ethenyl-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 400.569 42 2

[(1R,4′S)-5-amino-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 375.518 43 2

[(1R,4′S)-5- (dimethylamino)-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 403.572 44 2

[(1R,4′S)-6-ethyl-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 402.585 45 1

(4S,4′S)-2,3-dihydro- 1H-spiro[isoquinoline- 4,3′-pyrrolidin]-4′-yl(4- phenylpiperidin-1-yl) methanone 375.518 46 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](4- phenylpiperidin-1-yl) methanone 409.963 47 1

[(3R,4S)-1′,1′-dioxido- 2′,3′-dihydrospiro [pyrrolidine-3,4′- thiochromen]-4-yl](4- phenylpiperidin-1-yl) methanone 424.566 48 2

[(1R,4′S)-6-methyl-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 388.558 49 2

(4-phenylpiperidin-1- yl)[(1R,4′S)-6-(propan- 2-yl)-3,4-dihydro-2H- spiro[naphthalene-1,3′- pyrrolidin]-4′-yl] methanone 416.612 50 2

[(3R,4S)-2′-methyl- 7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinolin]-4-yl](4- phenylpiperidin-1-yl) methanone 389.545 51 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] [(2R,4S)-2-cyclohexyl- 4-phenylpiperidin-1-yl] methanone 492.11 52 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] [(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1-yl] methanone 492.11 53 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] [(2R,4R)-2-cyclohexyl- 4-phenylpiperidin-1-yl] methanone 492.11 54 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl][(2S,4S)- 2-cyclohexyl-4- phenylpiperidin-1-yl] methanone 492.11 55 2

[(1R,4′S)-6-(morpholin- 4-yl)-3,4-dihydro-2H- spiro[naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 459.637 56 2

[(1R,4′S)-6-tert-butyl- 3,4-dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1- yl)methanone 430.639 57 2

[(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1-yl] [(3R,4S)-7′,8′-dihydro- 6′H-spiro[pyrrolidine- 3,5′-quinolin]-4-yl] methanone 457.665 58 2

[(1R,4′S)-6- cyclopropyl-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1- yl)methanone 414.596 59 2

(4-phenylpiperidin-1- yl)[(1R,4′S)-6- (trifluoromethyl)-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl] methanone 442.529 60 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] [(2S,4R)-2,4- diphenylpiperidin-1- yl]methanone 486.062 61 2

[(2S,4R)-2,4- diphenylpiperidin-1- yl][(3R,4S)-2′-methyl- 7′,8′-dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] methanone 465.644 62 2

[(3R,4S)-2′-bromo-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] [(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1-yl] methanone 536.561 63 2

[(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1- yl][(3R,4S)-2′-methyl- 7′,8′-dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] methanone 471.692 64 2

[(1R,4′S)-6- (difluoromethyl)-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 424.539 65 2

[(1R,4′S)-6- (hydroxymethyl)-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 404.557 66 2

[(1R,4′S)-6- (aminomethyl)-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 403.572 67 2

[(1R,4′S)-6- (fluoromethyl)-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl](4- phenylpiperidin-1-yl) methanone 406.548 68 1

[(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1- yl][(4S,4′S)-2,3- dihydro-1H-spiro [isoquinoline-4,3′- pyrrolidin]-4′-yl] methanone 457.665 69 1

[(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1- yl][(4R,4′R)-2,3- dihydro-1H-spiro [isoquinoline-4,3′- pyrrolidin]-4′-yl] methanone 457.665 70 2

[(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1-yl] [(3R,4S)-2′-(propan-2- yl)-7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinolin]-4-yl] methanone 499.746 71 2

(4-phenylpiperidin-1- yl)[(1R,4′S)-6-(2,2,2- trifluoro-1- hydroxyethyl)-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl] methanone 472.556 72 2

[(3R,4S)-2′-methyl- 7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinolin]-4-yl] [(2S,4R)-4-phenyl-2- (propan-2-yl)piperidin- 1-yl]methanone 431.627 73 2

[(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1- yl][(3R,4S)-1′-oxido- 7′,8′-dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] methanone 473.664 74 2

[(2S,4R)-2-tert-butyl-4- phenylpiperidin-1-yl] [(3R,4S)-2′-methyl- 7′,8′-dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] methanone 445.654 75 1

(4-phenylpiperidin-1-yl) [(4S,4′S)-1H- spiro[isochromene-4,3′- pyrrolidin]-4′-yl] methanone 376.503 76 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl] [(2S,4R)-2-(pentan-3- yl)-4-phenylpiperidin-1- yl]methanone 480.099 77 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](2′- phenyl-1′H-spiro [indene-1,4′-piperidin]- 1′-yl)methanone 510.084 78 2

[(3R,4S)-2′-methyl- 7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinolin]-4-yl] [(2S,4R)-2-(pentan-3- yl)-4-phenylpiperidin-1- yl]methanone 459.681 79 2

[(2S,4R)-2-cyclohexyl- 4-phenylpiperidin-1-yl] [(1R,4′S)-6- (hydroxymethyl)-3,4- dihydro-2H-spiro [naphthalene-1,3′- pyrrolidin]-4′-yl] methanone 486.704 80 2

[(4S)-2′-chloro-7′,8′- dihydro-6'H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](4- phenyl-2- propylpiperidin-1-yl) methanone 453.052 81 2

[(4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl][2-(2- methylpropyl)-4- phenylpiperidin-1-yl] methanone 466.072 82 2

[(4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](4- phenyl-2- propylpiperidin-1- yl)methanone 466.072 83 2

[(4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl][2-(4- fluorophenyl)-4- phenylpiperidin-1-yl] methanone 504.052 84 1

2,3-dihydrospiro [chromene-4,3′- pyrrolidin]-4′-yl(2,4- diphenylpiperidin-1-yl) methanone 452.602 85 2

(6-bromo-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′-yl)[2- (4-fluorophenyl)-4- phenylpiperidin-1-yl] methanone 533.489 86 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](4- phenyl-2-propylazepan- 1-yl)methanone 466.072 87 2

(6-bromo-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′- yl)(2,4- diphenylpiperidin-1-yl) methanone 515.498 88 2

(2′-chloro-7′,8′-dihydro- 6′H-spiro[pyrrolidine- 3,5′-quinolin]-4-yl)(2,4- diphenylpiperidin-1-yl) methanone 486.062 89 1

2,3-dihydrospiro [chromene-4,3′- pyrrolidin]-4′-yl[4- phenyl-2-(prop-2-en-1- yl)piperidin-1-yl] methanone 416.568 90 1

2,3-dihydrospiro [chromene-4,3′- pyrrolidin]-4′-yl[2-(2- fluorophenyl)-4- phenylpiperidin-1-yl] methanone 470.592 91 1

2,3-dihydrospiro [chromene-4,3′- pyrrolidin]-4′-yl[2-(4- fluorophenyl)-4- phenylpiperidin-1-yl] methanone 470.592 92 2

(2,4-diphenylpiperidin- 1-yl)(6-ethyl-2,3- dihydrospiro[indene- 1,3′-pyrrolidin]-4′-yl) methanone 464.657 93 2

(3-benzylpiperidin-1- yl)[(3R,4S)-2′-chloro- 7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinolin]-4-yl] methanone 423.99 94 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](1′H- spiro[1-benzofuran-3,4′- piperidin-1′-yl) methanone 437.974 95 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](1,2- dihydro-1′H-spiro [indole-3,4′-piperidin]- 1′-yl)methanone 436.989 96 1

(2-butyl-2,3- dihydrospiro[chromene- 4,3′-pyrrolidin]-4′- yl)(2,4- diphenylpiperidin-1- yl)methanone 508.71 97 2

(2′-chloro-7′,8′-dihydro- 6′H-spiro[pyrrolidine- 3,5′-quinolin]-4-yl)(5- phenyl-2-propylazepan- 1-yl)methanone 466.072 98 2

(2′-chloro-7′,8′-dihydro- 6′H-spiro[pyrrolidine- 3,5′-quinolin]-4-yl)[4- phenyl-2-(prop-2-en-1- yl)piperidin-1-yl] methanone 450.029 99 2

(2′-chloro-7′,8′-dihydro- 6′H-spiro[pyrrolidine- 3,5′-quinolin]-4-yl)[2- (2-fluorophenyl)-4- phenylpiperidin-1-yl] methanone 504.052 100 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl][2-(3- methylphenyl)-4- phenylpiperidin-1-yl] methanone 500.089 101 1

(4R,4′S)-2,3- dihydrospiro[chromene- 4,3′-pyrrolidin]-4′- yl[(2S,4R)-2,4- diphenylpiperidin-1-yl] methanone 452.602 102 1

[(2S,4R)-2,4- diphenylpiperidin-1- yl][(4R,4′S)-2-methyl- 2,3-dihydrospiro [chromene-4,3′- pyrrolidin]-4′-yl] methanone 466.629 103 1

[(4R,4′S)-2-butyl-2,3- dihydrospiro[chromene- 4,3′-pyrrolidin]-4′-yl] [(2S,4R)-2,4- diphenylpiperidin-1-yl] methanone 508.71 104 2

[(4R,4′S)-6-chloro-2,3- dihydrospiro[chromene- 4,3′-pyrrolidin]-4′-yl] [(2S,4R)-2,4- diphenylpiperidin-1-yl] methanone 487.047 105 2

[(4R,4′S)-6-chloro-7- methyl-2,3- dihydrospiro[chromene- 4,3′-pyrrolidin]-4′-yl] [(2S,4R)-2,4- diphenylpiperidin-1-yl] methanone 501.074 106 2

[(3R,4S)-2′-chloro-1′- oxido-7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinolin]-4-yl] [(2R,4S)-2,4- diphenylpiperidin-1-yl] methanone 502.061 107 2

[(2R,4S)-2,4- diphenylpiperidin-1- yl][(3R,4S)-2′-ethyl- 7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinolin]-4-yl] methanone 479.671 108 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl][2′-(4- fluorophenyl)-1′H- spiro[indene-1,4′- piperidin]-1′-yl] methanone 528.075 109 2

[(3R,4S)-2′-chloro-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinolin]-4-yl](2′- phenyl-1′H-spiro [indene-1,4′-piperidin]- 1′-yl)methanone 510.084 110 1

(4R,4′S)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-1,5,6,7- tetrahydrospiro[indole- 4,3′-pyrrolidine] 439.59 111 1

(4R,4′S)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-6,7- dihydro-5H-spiro[1- benzothiophene-4,3′- pyrrolidine] 456.64 112 1

(4R,4′S)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-6,7- dihydro-5H-spiro[1- benzofuran-4,3′- pyrrolidine] 440.58 113 1

(4′S,7S)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-2-methyl- 5,6-dihydro-4H- spiro[1,3-benzothiazole- 7,3′-pyrrolidine] 471.66 114 1

(4′S,7S)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-5,6- dihydro-4H-spiro[1- benzothiophene-7,3′- pyrrolidine] 456.64 115 1

(4′S,7S)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-5,6- dihydro-4H-spiro[1- benzofuran-7,3′- pyrrolidine] 440.58 116 1

(3R,4S)-4-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-7′-methyl- 2′,3′- dihydrospiro[pyrrolidine- 3,4′-thiopyrano[2,3-b] pyridine] 483.67 117 2

(3S,4S)-2′-chloro-4- {[(2S,4R)-2,4- diphenylpiperidin-1- yl]carbonyl}-6′,7′- dihydro-5′H-spiro [pyrrolidine-3,8′- quinoline] 486.05 118 2

(3R,4S)-3′-chloro-4- {[(2S,4R)-2,4- diphenylpiperidin-1- yl]carbonyl}-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinoline] 486.05 119 1

(3S,4S)-4-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-2′-phenyl- 6′,7′-dihydro-5′H- spiro[pyrrolidine-3,8′- quinoline] 527.7 120 1

(3R,4S)-4-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-3′-methyl- 7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinoline] 464.64 121 1

(3R,4S)-4-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-4′-methyl- 7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinoline] 464.64 122 1

(3S,4S)-4-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-3′-methyl- 6′,7′-dihydro-5′H- spiro[pyrrolidine-3,8′- quinoline] 464.64 123 1

(3R,4S)-4-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-2′-methyl- 7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinazoline] 465.63 124 1

(3R,4S)-4-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-2′-phenyl- 7′,8′-dihydro-6′H- spiro[pyrrolidine-3,5′- quinazoline] 527.7 125 1

(3S,4S)-4-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinoxaline] 451.6 126 1

(3R,4S)-4-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-4′- (trifluoromethyl)-7′,8′- dihydro-6′H-spiro [pyrrolidine-3,5′- quinoline] 518.61 127 1

(4′S,8R)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-1,3- dimethyl-6,7-dihydro- 5H-spiro[isoquinoline- 8,3′-pyrrolidine] 478.67 128 1

(1R,4′S)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-6,8- dimethyl-3,4-dihydro- 2H-spiro[naphthalene- 1,3′-pyrrolidine] 478.67 129 1

(1R,4′S)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}- 3,4,5,6,7,8-hexahydro- 2H-spiro[acridine-1,3′- pyrrolidine] 504.7 130 1

(4′S,9R)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}- 1,2,3,6,7,8- hexahydrospiro[cyclope nta[c]quinoline-9,3′- pyrrolidine] 520.75 131 1

(4R,4′S)-4′-{[(2S,4R)- 2,4-diphenylpiperidin-1- yl]carbonyl}-2,2- dimethyl-2,3- dihydrospiro[chromene- 4,3′-pyrrolidine] 479.65 132 2

(4R,4′S)-7-bromo-4′- {[(2S,4R)-2,4- diphenylpiperidin-1- yl]carbonyl}-2,3- dihydrospiro[chromene- 4,3′-pyrrolidine] 530.5 133 2

(3S,4′S)-6-bromo-4′- {[(2S,4R)-2,4- diphenylpiperidin-1- yl]carbonyl}spiro[1- benzofuran-3,3′- pyrrolidine] 516.47 134 2

(1R,4′S)-5-bromo-4′- {[(2S,4R)-2,4- diphenylpiperidin-1- yl]carbonyl}-2,3- dihydrospiro[indene- 1,3′-pyrrolidine] 514.5 135 1

(1S,4′S)-7-bromo-4′- {[(2S,4R)-2,4- diphenylpiperidin-1- yl]carbonyl}-4,5- dihydrospiro[3- benzoxepine-1,3′- pyrrolidine] 465.63

Compounds in Table 2 having a basic group or acidic group are depicted and named as the free base acid. Depending on the reaction and purification conditions, various compounds in Table 1 having a basic group were isolated in either the free base form, or as a salt (such as HCl salt), or in both free base and salt forms.

The following compounds were prepared similar to Examples 1 to 3 using the starting materials and methods described herein, and applying the knowledge of one of skilled in the art.

TABLE 3 Ex. Parent No. Scheme Structure MW 136 2

462.594 137 2

532.68 138 2

534.696 139 2

478.705 140 2

522.685 141 2

470.564 142 2

448.611 143 2

556.674 144 2

487.57 145 2

514.686 146 2

524.657 147 2

556.553 148 2

498.715 149 2

537.546 150 2

507.673 151 2

484.668 152 2

486.704 153 2

471.677 154 2

496.699 155 2

478.554 156 2

555.569 157 2

506.666 158 2

576.646 159 2

488.555 160 2

472.558 161 2

471.571 162 2

476.649 163 2

514.714 164 2

537.546 165 2

533.736 166 2

525.663 167 2

501.554 168 2

452.574 169 2

462.638 170 2

489.664 171 2

573.68 172 2

502.66 173 2

537.656 174 2

522.685 175 2

524.657 176 2

476.665 177 2

542.647 178 2

445.595 179 2

488.592 180 2

473.708 181 2

498.715 182 2

491.655 183 2

524.657 184 2

488.676 185 2

502.703 186 2

450.583 187 2

446.595 188 2

610.646 189 2

474.693 190 2

592.655 191 2

544.663 192 2

570.673 193 2

488.555 194 2

501.675 195 2

420.557 196 2

542.647 197 2

420.557 198 2

507.673 199 2

532.677 200 2

525.663 201 2

507.673 202 2

434.584 203 2

522.685 204 2

476.665 205 2

521.149 206 2

556.674 207 2

591.671 208 2

543.679 209 2

542.74 210 2

505.682 211 2

526.651 212 2

508.66 213 2

560.731 214 2

509.763 215 2

497.752 216 2

481.709 217 2

545.709 218 2

559.736 219 2

471.692 220 2

500.734 221 2

397.481 222 2

413.543 223 2

412.493 224 2

466.072 225 2

536.561 226 2

465.644 227 2

479.671 228 2

524.55 229 2

459.681 230 2

406.529 231 2

609.661 232 2

525.663 233 2

507.673 234 2

501.675 235 2

431.539 236 2

524.657 237 2

446.595 238 2

448.611 239 2

471.692 240 2

464.056 241 2

452.045 242 2

473.664 243 2

486.583 244 2

450.029 245 2

488.676 246 2

555.69 247 2

503.709 248 2

510.1 249 2

510.1 250 2

494.748 251 2

506.71 252 2

482.628 253 2

466.629 254 2

488.676 255 2

553.773 256 2

539.746 257 2

545.149 258 2

565.784 259 2

551.757 260 2

530.513 261 2

480.656 262 2

476.665 264 2

452.602 265 2

502.703 266 2

503.709 267 2

485.719 268 2

459.681 269 2

459.681 270 2

501.718 271 2

522.136 272 2

512.701 273 2

502.703 274 2

541.663 275 2

493.097 276 2

498.089 277 2

481.086 278 2

518.721 279 2

502.706 280 2

514.714 281 2

555.69 282 2

555.69 283 2

471.692 284 2

566.587 285 2

488.679 286 2

499.746 287 2

505.682 288 2

486.704 289 2

474.693 290 2

531.498 291 2

554.702 292 2

487.691 293 2

488.676 294 2

514.686 295 2

501.718 296 2

539.139 297 2

504.694 298 2

529.729 299 2

500.731 300 2

565.6 301 2

487.691 302 2

488.676 303 2

557.16 304 2

523.672 305 2

475.68 306 2

480.721 307 2

480.721 308 2

466.694 309 2

528.091 310 2

528.091 311 2

507.673 312 2

460.668 313 2

489.664 314 2

573.773 315 2

506.016 316 2

528.091 317 2

472.677 318 2

460.665 319 2

537.546 320 2

525.534 321 2

492.732 322 2

474.693 323 2

503.709 324 2

503.709 325 2

506.759 326 2

522.685 327 2

508.109 328 2

534.721 329 2

590.104 330 2

487.691 331 2

487.691 332 2

517.742 333 2

499.702 334 2

485.719 335 2

499.746 336 2

487.05 337 2

482.675 338 2

494.748 339 2

492.732 340 2

506.759 341 2

487.691 342 2

486.704 343 2

514.758 344 2

506.093 345 2

518.721 346 2

518.721 347 2

495.708 348 2

507.125 349 2

486.704 350 2

485.719 351 2

522.759 352 2

513.699 353 2

492.658 354 2

489.707 355 2

521.771 356 2

593.613 357 2

481.687 358 2

494.082 359 2

487.691 360 2

520.787 361 2

520.787 362 2

527.128 363 2

463.691 364 2

539.139 365 2

506.759 366 2

486.704 367 2

478.001 368 2

578.721 369 2

472.679 370 2

560.731 371 2

508.732 372 2

492.732 373 2

496.696 374 2

473.664 375 2

514.761 376 2

461.656 377 2

460.668 378 2

471.692 379 2

490.053 380 2

627.723 381 2

478.705 382 2

494.748 383 2

536.539 384 2

520.787 385 2

507.673 386 2

460.688 387 2

472.679 388 2

476.026 389 2

532.798 390 2

506.759 391 2

509.113 392 2

562.604 393 2

492.732 394 2

479.69 395 2

461.653 396 2

526.75 397 2

500.712 398 2

492.683 399 2

504.694 400 2

518.721 401 2

513.101 402 2

460.665 402 2

528.091 404 2

504.694 405 2

472.679 406 2

493.717 407 2

493.732 408 2

497.93 409 2

525.112 410 2

485.719 411 2

505.682 412 2

506.137 413 2

550.588 414 2

534.77 415 2

501.718 416 2

485.719 417 2

489.682 418 2

492.732 419 2

520.743 420 2

517.718 421 2

501.718 422 2

472.677 423 2

542.17 424 2

536.561 425 2

488.695 426 2

506.137 427 2

490.667 428 2

844.778 429 2

513.73 430 2

492.732 431 2

506.759 432 2

542.17 433 2

478.656 434 2

493.095 435 2

478.705 436 2

506.137 437 2

401.863 438 2

498.136 439 2

482.071 440 2

491.692 441 2

493.717 442 2

495.708 443 2

585.214 444 2

544.186 445 2

549.162 446 2

639.186 447 2

493.717 448 2

578.642 449 2

501.675 450 2

499.746 451 2

493.095 452 2

537.546 453 2

491.745 454 2

474.668 455 2

564.177 456 2

585.162 457 2

517.718 458 2

507.744 459 2

491.745 460 2

495.708 461 2

505.682 462 2

510.1 463 2

485.719 464 2

473.708 465 2

510.1 466 2

494.082 467 2

503.691 468 2

495.681 469 2

487.691 470 2

498.136 471 2

507.744 472 2

640.67 473 2

593.613 474 2

614.651 475 2

560.108 476 2

477.718 477 2

459.637 478 2

655.685 479 2

594.598 480 2

676.722 481 2

536.561 482 2

604.68 483 2

578.598 484 2

510.1 485 2

506.137 486 2

507.125 487 2

626.687 488 2

473.664 489 2

528.091 490 2

477.718 491 2

522.136 492 2

506.137 493 2

521.546 494 2

490.667 495 2

485.697 496 2

492.008 497 2

535.551 498 2

481.083 499 2

508.109 500 2

506.093 501 2

477.718 502 2

536.163 503 2

525.112

Compounds in Table 3 having a basic group or acidic group are depicted and named either as the free base acid or as the salt thereof. Depending on the reaction and purification conditions, the compounds of Table 1 may be isolated in either the free base form, or as a salt (such as HCl salt), or in both free base and salt forms.

The utility of the compounds in accordance with the present invention as inhibitors of β-secretase enzyme activity may be demonstrated by methodology known in the art. Enzyme inhibition is determined as follows.

ECL Assay: A homogeneous end point electrochemiluminescence (ECL) assay is performed using a biotinylated BACE substrate. The Km of the substrate is approximated at 50 μM. A typical reaction contains approximately 0.6 nM enzyme, 0.25 μM of the substrate, and buffer (50 mM Pipes, pH 6.5, 0.1 mg/ml BSA, 0.2% CHAPS, 15 mM EDTA and 1 mM deferoxamine) in a total reaction volume of 100 μl. The reaction proceeds for 1-2 hrs and is then stopped by the addition of 150 μL of a quench cocktail solution (25 μl M Tris-HCl, pH 8.0, 50 μl INC buffer (2% BSA, 0.2% Tween-20 and 0.05% sodium azide diluted in Phosphate buffered saline (PBS) plus 75 μL PBS), containing Streptavidin coated magnetic beads and ruthenylated antibody which specifically recognizes the C-terminal residue of the product. The samples are subjected to M-384 (Igen Inc., Gaithersburg, Md.) analysis. Under these conditions, less than 10% of substrate is processed by BACE 1. The enzyme used in these studies is soluble (transmembrane domain and cytoplasmic extension excluded) human protein produced in a baculovirus expression system. To measure the inhibitory potency for compounds, 10 concentrations of inhibitors are prepared starting from 200 μM with three fold series dilution. Solutions of the inhibitor in DMSO are included in the reaction mixture (final DMSO concentration is 10%). All experiments are conducted at rt using the standard reaction conditions described above. To determine the IC₅₀ of the compound, a four parameter equation is used for curve fitting. The errors in reproducing the dissociation constants are typically less than two-fold.

In particular, the compounds of the following examples had activity in inhibiting the beta-secretase enzyme in the aforementioned assay, generally with an IC₅₀ from about 1 nM to 200 μM. Such a result is indicative of the intrinsic activity of the compounds in use as inhibitors of beta-secretase enzyme activity.

Several methods for preparing the compounds of this invention are illustrated in the Schemes and Examples herein. Starting materials are made according to procedures known in the art or as illustrated herein. The following examples are provided so that the invention might be more fully understood. These examples are illustrative only and should not be construed as limiting the invention in any way.

Exemplary IC₅₀ values for representative compounds of the invention (as described in the following Examples) are provided below in Table 3.

TABLE 3 Example IC₅₀(μM) 3 2.19 7 22 10 20 19 0.92 21 0.071 30 14 31 0.024 38 12 44 19 77 0.2 100 0.45

The following abbreviations are used throughout the text:

Me: methyl

Et: ethyl

Bu: butyl

t-Bu: tert-butyl

i-Bu: iso-butyl

Pr: propyl

i-Pr: iso-propyl

Ar: aryl

Ph: phenyl

Bn: benzyl

BOP: benzotriazolyl-N-oxy-tris(dimethylamino)phosphonium hexafluorophosphate

Boc: tert butyloxycarbonyl

TFA: trifluoro acetic acid

THF: tetrahydrofuran

Ac: acetyl

aq: aqueous

rt: room temperature

h: hours

min: minutes 

What is claimed is:
 1. A compound of formula (I)

wherein: R¹ is selected from the group consisting of (1) hydrogen (2) C₁₋₆alkyl, (3) C₃₋₉ cycloalkyl, and (4) phenyl, wherein said alkyl, cycloalkyl or phenyl R¹ moiety is optionally substituted with one or more (a) halo, (b) —OH, (c) —CN, (d) —C₁₋₆ alkyl (e) —C₃₋₆ cycloalkyl, or (f) —O—C₁₋₆ alkyl; R² is hydrogen; R³ is selected from the group consisting of: (1) hydrogen, (2) C₆₋₁₀aryl (for example, phenyl), and (3) heteroaryl, wherein said aryl or heteroaryl R³ moiety is optionally substituted with one or more (a) halo, (b) —C₁₋₆ alkyl, wherein said alkyl is optionally substituted with one or more halogen, and (c) —O—C₁₋₆ alkyl; R¹¹ is selected from the group consisting of (1) hydrogen (2) C₁₋₆alkyl, (3) C₃₋₆ cycloalkyl, and (4) phenyl, wherein said alkyl, cycloalkyl or phenyl R¹¹ moiety is optionally substituted with one or more (a) halo, (b) —OH, (c) —CN, (d) —C₁₋₆ alkyl (e) —C₃₋₆ cycloalkyl, or (f) —O—C₁₋₆ alkyl.
 2. A compound of claim 1, wherein R¹ is selected from the group consisting of: hydrogen, phenyl (optionally substituted with halogen), and cyclohexyl.
 3. A compound of claim 2, wherein R³ is hydrogen or unsubstituted phenyl.
 4. A compound, or a pharmaceutically acceptable salt thereof, said compound having a structure: Structure

and


5. A compound, or a pharmaceutically acceptable salt thereof, said compound having a structure: Structure

and


6. A pharmaceutical composition, comprising a compound of claim 1, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.
 7. A pharmaceutical composition, comprising a compound of claim 5, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.
 8. A pharmaceutical composition, comprising a compound of claim 4, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier. 